aboutsummaryrefslogtreecommitdiff
path: root/shell/ash.c
blob: bfa4a8c6d6708d277b119286809aefdd06d8fe47 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
6587
6588
6589
6590
6591
6592
6593
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
6618
6619
6620
6621
6622
6623
6624
6625
6626
6627
6628
6629
6630
6631
6632
6633
6634
6635
6636
6637
6638
6639
6640
6641
6642
6643
6644
6645
6646
6647
6648
6649
6650
6651
6652
6653
6654
6655
6656
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669
6670
6671
6672
6673
6674
6675
6676
6677
6678
6679
6680
6681
6682
6683
6684
6685
6686
6687
6688
6689
6690
6691
6692
6693
6694
6695
6696
6697
6698
6699
6700
6701
6702
6703
6704
6705
6706
6707
6708
6709
6710
6711
6712
6713
6714
6715
6716
6717
6718
6719
6720
6721
6722
6723
6724
6725
6726
6727
6728
6729
6730
6731
6732
6733
6734
6735
6736
6737
6738
6739
6740
6741
6742
6743
6744
6745
6746
6747
6748
6749
6750
6751
6752
6753
6754
6755
6756
6757
6758
6759
6760
6761
6762
6763
6764
6765
6766
6767
6768
6769
6770
6771
6772
6773
6774
6775
6776
6777
6778
6779
6780
6781
6782
6783
6784
6785
6786
6787
6788
6789
6790
6791
6792
6793
6794
6795
6796
6797
6798
6799
6800
6801
6802
6803
6804
6805
6806
6807
6808
6809
6810
6811
6812
6813
6814
6815
6816
6817
6818
6819
6820
6821
6822
6823
6824
6825
6826
6827
6828
6829
6830
6831
6832
6833
6834
6835
6836
6837
6838
6839
6840
6841
6842
6843
6844
6845
6846
6847
6848
6849
6850
6851
6852
6853
6854
6855
6856
6857
6858
6859
6860
6861
6862
6863
6864
6865
6866
6867
6868
6869
6870
6871
6872
6873
6874
6875
6876
6877
6878
6879
6880
6881
6882
6883
6884
6885
6886
6887
6888
6889
6890
6891
6892
6893
6894
6895
6896
6897
6898
6899
6900
6901
6902
6903
6904
6905
6906
6907
6908
6909
6910
6911
6912
6913
6914
6915
6916
6917
6918
6919
6920
6921
6922
6923
6924
6925
6926
6927
6928
6929
6930
6931
6932
6933
6934
6935
6936
6937
6938
6939
6940
6941
6942
6943
6944
6945
6946
6947
6948
6949
6950
6951
6952
6953
6954
6955
6956
6957
6958
6959
6960
6961
6962
6963
6964
6965
6966
6967
6968
6969
6970
6971
6972
6973
6974
6975
6976
6977
6978
6979
6980
6981
6982
6983
6984
6985
6986
6987
6988
6989
6990
6991
6992
6993
6994
6995
6996
6997
6998
6999
7000
7001
7002
7003
7004
7005
7006
7007
7008
7009
7010
7011
7012
7013
7014
7015
7016
7017
7018
7019
7020
7021
7022
7023
7024
7025
7026
7027
7028
7029
7030
7031
7032
7033
7034
7035
7036
7037
7038
7039
7040
7041
7042
7043
7044
7045
7046
7047
7048
7049
7050
7051
7052
7053
7054
7055
7056
7057
7058
7059
7060
7061
7062
7063
7064
7065
7066
7067
7068
7069
7070
7071
7072
7073
7074
7075
7076
7077
7078
7079
7080
7081
7082
7083
7084
7085
7086
7087
7088
7089
7090
7091
7092
7093
7094
7095
7096
7097
7098
7099
7100
7101
7102
7103
7104
7105
7106
7107
7108
7109
7110
7111
7112
7113
7114
7115
7116
7117
7118
7119
7120
7121
7122
7123
7124
7125
7126
7127
7128
7129
7130
7131
7132
7133
7134
7135
7136
7137
7138
7139
7140
7141
7142
7143
7144
7145
7146
7147
7148
7149
7150
7151
7152
7153
7154
7155
7156
7157
7158
7159
7160
7161
7162
7163
7164
7165
7166
7167
7168
7169
7170
7171
7172
7173
7174
7175
7176
7177
7178
7179
7180
7181
7182
7183
7184
7185
7186
7187
7188
7189
7190
7191
7192
7193
7194
7195
7196
7197
7198
7199
7200
7201
7202
7203
7204
7205
7206
7207
7208
7209
7210
7211
7212
7213
7214
7215
7216
7217
7218
7219
7220
7221
7222
7223
7224
7225
7226
7227
7228
7229
7230
7231
7232
7233
7234
7235
7236
7237
7238
7239
7240
7241
7242
7243
7244
7245
7246
7247
7248
7249
7250
7251
7252
7253
7254
7255
7256
7257
7258
7259
7260
7261
7262
7263
7264
7265
7266
7267
7268
7269
7270
7271
7272
7273
7274
7275
7276
7277
7278
7279
7280
7281
7282
7283
7284
7285
7286
7287
7288
7289
7290
7291
7292
7293
7294
7295
7296
7297
7298
7299
7300
7301
7302
7303
7304
7305
7306
7307
7308
7309
7310
7311
7312
7313
7314
7315
7316
7317
7318
7319
7320
7321
7322
7323
7324
7325
7326
7327
7328
7329
7330
7331
7332
7333
7334
7335
7336
7337
7338
7339
7340
7341
7342
7343
7344
7345
7346
7347
7348
7349
7350
7351
7352
7353
7354
7355
7356
7357
7358
7359
7360
7361
7362
7363
7364
7365
7366
7367
7368
7369
7370
7371
7372
7373
7374
7375
7376
7377
7378
7379
7380
7381
7382
7383
7384
7385
7386
7387
7388
7389
7390
7391
7392
7393
7394
7395
7396
7397
7398
7399
7400
7401
7402
7403
7404
7405
7406
7407
7408
7409
7410
7411
7412
7413
7414
7415
7416
7417
7418
7419
7420
7421
7422
7423
7424
7425
7426
7427
7428
7429
7430
7431
7432
7433
7434
7435
7436
7437
7438
7439
7440
7441
7442
7443
7444
7445
7446
7447
7448
7449
7450
7451
7452
7453
7454
7455
7456
7457
7458
7459
7460
7461
7462
7463
7464
7465
7466
7467
7468
7469
7470
7471
7472
7473
7474
7475
7476
7477
7478
7479
7480
7481
7482
7483
7484
7485
7486
7487
7488
7489
7490
7491
7492
7493
7494
7495
7496
7497
7498
7499
7500
7501
7502
7503
7504
7505
7506
7507
7508
7509
7510
7511
7512
7513
7514
7515
7516
7517
7518
7519
7520
7521
7522
7523
7524
7525
7526
7527
7528
7529
7530
7531
7532
7533
7534
7535
7536
7537
7538
7539
7540
7541
7542
7543
7544
7545
7546
7547
7548
7549
7550
7551
7552
7553
7554
7555
7556
7557
7558
7559
7560
7561
7562
7563
7564
7565
7566
7567
7568
7569
7570
7571
7572
7573
7574
7575
7576
7577
7578
7579
7580
7581
7582
7583
7584
7585
7586
7587
7588
7589
7590
7591
7592
7593
7594
7595
7596
7597
7598
7599
7600
7601
7602
7603
7604
7605
7606
7607
7608
7609
7610
7611
7612
7613
7614
7615
7616
7617
7618
7619
7620
7621
7622
7623
7624
7625
7626
7627
7628
7629
7630
7631
7632
7633
7634
7635
7636
7637
7638
7639
7640
7641
7642
7643
7644
7645
7646
7647
7648
7649
7650
7651
7652
7653
7654
7655
7656
7657
7658
7659
7660
7661
7662
7663
7664
7665
7666
7667
7668
7669
7670
7671
7672
7673
7674
7675
7676
7677
7678
7679
7680
7681
7682
7683
7684
7685
7686
7687
7688
7689
7690
7691
7692
7693
7694
7695
7696
7697
7698
7699
7700
7701
7702
7703
7704
7705
7706
7707
7708
7709
7710
7711
7712
7713
7714
7715
7716
7717
7718
7719
7720
7721
7722
7723
7724
7725
7726
7727
7728
7729
7730
7731
7732
7733
7734
7735
7736
7737
7738
7739
7740
7741
7742
7743
7744
7745
7746
7747
7748
7749
7750
7751
7752
7753
7754
7755
7756
7757
7758
7759
7760
7761
7762
7763
7764
7765
7766
7767
7768
7769
7770
7771
7772
7773
7774
7775
7776
7777
7778
7779
7780
7781
7782
7783
7784
7785
7786
7787
7788
7789
7790
7791
7792
7793
7794
7795
7796
7797
7798
7799
7800
7801
7802
7803
7804
7805
7806
7807
7808
7809
7810
7811
7812
7813
7814
7815
7816
7817
7818
7819
7820
7821
7822
7823
7824
7825
7826
7827
7828
7829
7830
7831
7832
7833
7834
7835
7836
7837
7838
7839
7840
7841
7842
7843
7844
7845
7846
7847
7848
7849
7850
7851
7852
7853
7854
7855
7856
7857
7858
7859
7860
7861
7862
7863
7864
7865
7866
7867
7868
7869
7870
7871
7872
7873
7874
7875
7876
7877
7878
7879
7880
7881
7882
7883
7884
7885
7886
7887
7888
7889
7890
7891
7892
7893
7894
7895
7896
7897
7898
7899
7900
7901
7902
7903
7904
7905
7906
7907
7908
7909
7910
7911
7912
7913
7914
7915
7916
7917
7918
7919
7920
7921
7922
7923
7924
7925
7926
7927
7928
7929
7930
7931
7932
7933
7934
7935
7936
7937
7938
7939
7940
7941
7942
7943
7944
7945
7946
7947
7948
7949
7950
7951
7952
7953
7954
7955
7956
7957
7958
7959
7960
7961
7962
7963
7964
7965
7966
7967
7968
7969
7970
7971
7972
7973
7974
7975
7976
7977
7978
7979
7980
7981
7982
7983
7984
7985
7986
7987
7988
7989
7990
7991
7992
7993
7994
7995
7996
7997
7998
7999
8000
8001
8002
8003
8004
8005
8006
8007
8008
8009
8010
8011
8012
8013
8014
8015
8016
8017
8018
8019
8020
8021
8022
8023
8024
8025
8026
8027
8028
8029
8030
8031
8032
8033
8034
8035
8036
8037
8038
8039
8040
8041
8042
8043
8044
8045
8046
8047
8048
8049
8050
8051
8052
8053
8054
8055
8056
8057
8058
8059
8060
8061
8062
8063
8064
8065
8066
8067
8068
8069
8070
8071
8072
8073
8074
8075
8076
8077
8078
8079
8080
8081
8082
8083
8084
8085
8086
8087
8088
8089
8090
8091
8092
8093
8094
8095
8096
8097
8098
8099
8100
8101
8102
8103
8104
8105
8106
8107
8108
8109
8110
8111
8112
8113
8114
8115
8116
8117
8118
8119
8120
8121
8122
8123
8124
8125
8126
8127
8128
8129
8130
8131
8132
8133
8134
8135
8136
8137
8138
8139
8140
8141
8142
8143
8144
8145
8146
8147
8148
8149
8150
8151
8152
8153
8154
8155
8156
8157
8158
8159
8160
8161
8162
8163
8164
8165
8166
8167
8168
8169
8170
8171
8172
8173
8174
8175
8176
8177
8178
8179
8180
8181
8182
8183
8184
8185
8186
8187
8188
8189
8190
8191
8192
8193
8194
8195
8196
8197
8198
8199
8200
8201
8202
8203
8204
8205
8206
8207
8208
8209
8210
8211
8212
8213
8214
8215
8216
8217
8218
8219
8220
8221
8222
8223
8224
8225
8226
8227
8228
8229
8230
8231
8232
8233
8234
8235
8236
8237
8238
8239
8240
8241
8242
8243
8244
8245
8246
8247
8248
8249
8250
8251
8252
8253
8254
8255
8256
8257
8258
8259
8260
8261
8262
8263
8264
8265
8266
8267
8268
8269
8270
8271
8272
8273
8274
8275
8276
8277
8278
8279
8280
8281
8282
8283
8284
8285
8286
8287
8288
8289
8290
8291
8292
8293
8294
8295
8296
8297
8298
8299
8300
8301
8302
8303
8304
8305
8306
8307
8308
8309
8310
8311
8312
8313
8314
8315
8316
8317
8318
8319
8320
8321
8322
8323
8324
8325
8326
8327
8328
8329
8330
8331
8332
8333
8334
8335
8336
8337
8338
8339
8340
8341
8342
8343
8344
8345
8346
8347
8348
8349
8350
8351
8352
8353
8354
8355
8356
8357
8358
8359
8360
8361
8362
8363
8364
8365
8366
8367
8368
8369
8370
8371
8372
8373
8374
8375
8376
8377
8378
8379
8380
8381
8382
8383
8384
8385
8386
8387
8388
8389
8390
8391
8392
8393
8394
8395
8396
8397
8398
8399
8400
8401
8402
8403
8404
8405
8406
8407
8408
8409
8410
8411
8412
8413
8414
8415
8416
8417
8418
8419
8420
8421
8422
8423
8424
8425
8426
8427
8428
8429
8430
8431
8432
8433
8434
8435
8436
8437
8438
8439
8440
8441
8442
8443
8444
8445
8446
8447
8448
8449
8450
8451
8452
8453
8454
8455
8456
8457
8458
8459
8460
8461
8462
8463
8464
8465
8466
8467
8468
8469
8470
8471
8472
8473
8474
8475
8476
8477
8478
8479
8480
8481
8482
8483
8484
8485
8486
8487
8488
8489
8490
8491
8492
8493
8494
8495
8496
8497
8498
8499
8500
8501
8502
8503
8504
8505
8506
8507
8508
8509
8510
8511
8512
8513
8514
8515
8516
8517
8518
8519
8520
8521
8522
8523
8524
8525
8526
8527
8528
8529
8530
8531
8532
8533
8534
8535
8536
8537
8538
8539
8540
8541
8542
8543
8544
8545
8546
8547
8548
8549
8550
8551
8552
8553
8554
8555
8556
8557
8558
8559
8560
8561
8562
8563
8564
8565
8566
8567
8568
8569
8570
8571
8572
8573
8574
8575
8576
8577
8578
8579
8580
8581
8582
8583
8584
8585
8586
8587
8588
8589
8590
8591
8592
8593
8594
8595
8596
8597
8598
8599
8600
8601
8602
8603
8604
8605
8606
8607
8608
8609
8610
8611
8612
8613
8614
8615
8616
8617
8618
8619
8620
8621
8622
8623
8624
8625
8626
8627
8628
8629
8630
8631
8632
8633
8634
8635
8636
8637
8638
8639
8640
8641
8642
8643
8644
8645
8646
8647
8648
8649
8650
8651
8652
8653
8654
8655
8656
8657
8658
8659
8660
8661
8662
8663
8664
8665
8666
8667
8668
8669
8670
8671
8672
8673
8674
8675
8676
8677
8678
8679
8680
8681
8682
8683
8684
8685
8686
8687
8688
8689
8690
8691
8692
8693
8694
8695
8696
8697
8698
8699
8700
8701
8702
8703
8704
8705
8706
8707
8708
8709
8710
8711
8712
8713
8714
8715
8716
8717
8718
8719
8720
8721
8722
8723
8724
8725
8726
8727
8728
8729
8730
8731
8732
8733
8734
8735
8736
8737
8738
8739
8740
8741
8742
8743
8744
8745
8746
8747
8748
8749
8750
8751
8752
8753
8754
8755
8756
8757
8758
8759
8760
8761
8762
8763
8764
8765
8766
8767
8768
8769
8770
8771
8772
8773
8774
8775
8776
8777
8778
8779
8780
8781
8782
8783
8784
8785
8786
8787
8788
8789
8790
8791
8792
8793
8794
8795
8796
8797
8798
8799
8800
8801
8802
8803
8804
8805
8806
8807
8808
8809
8810
8811
8812
8813
8814
8815
8816
8817
8818
8819
8820
8821
8822
8823
8824
8825
8826
8827
8828
8829
8830
8831
8832
8833
8834
8835
8836
8837
8838
8839
8840
8841
8842
8843
8844
8845
8846
8847
8848
8849
8850
8851
8852
8853
8854
8855
8856
8857
8858
8859
8860
8861
8862
8863
8864
8865
8866
8867
8868
8869
8870
8871
8872
8873
8874
8875
8876
8877
8878
8879
8880
8881
8882
8883
8884
8885
8886
8887
8888
8889
8890
8891
8892
8893
8894
8895
8896
8897
8898
8899
8900
8901
8902
8903
8904
8905
8906
8907
8908
8909
8910
8911
8912
8913
8914
8915
8916
8917
8918
8919
8920
8921
8922
8923
8924
8925
8926
8927
8928
8929
8930
8931
8932
8933
8934
8935
8936
8937
8938
8939
8940
8941
8942
8943
8944
8945
8946
8947
8948
8949
8950
8951
8952
8953
8954
8955
8956
8957
8958
8959
8960
8961
8962
8963
8964
8965
8966
8967
8968
8969
8970
8971
8972
8973
8974
8975
8976
8977
8978
8979
8980
8981
8982
8983
8984
8985
8986
8987
8988
8989
8990
8991
8992
8993
8994
8995
8996
8997
8998
8999
9000
9001
9002
9003
9004
9005
9006
9007
9008
9009
9010
9011
9012
9013
9014
9015
9016
9017
9018
9019
9020
9021
9022
9023
9024
9025
9026
9027
9028
9029
9030
9031
9032
9033
9034
9035
9036
9037
9038
9039
9040
9041
9042
9043
9044
9045
9046
9047
9048
9049
9050
9051
9052
9053
9054
9055
9056
9057
9058
9059
9060
9061
9062
9063
9064
9065
9066
9067
9068
9069
9070
9071
9072
9073
9074
9075
9076
9077
9078
9079
9080
9081
9082
9083
9084
9085
9086
9087
9088
9089
9090
9091
9092
9093
9094
9095
9096
9097
9098
9099
9100
9101
9102
9103
9104
9105
9106
9107
9108
9109
9110
9111
9112
9113
9114
9115
9116
9117
9118
9119
9120
9121
9122
9123
9124
9125
9126
9127
9128
9129
9130
9131
9132
9133
9134
9135
9136
9137
9138
9139
9140
9141
9142
9143
9144
9145
9146
9147
9148
9149
9150
9151
9152
9153
9154
9155
9156
9157
9158
9159
9160
9161
9162
9163
9164
9165
9166
9167
9168
9169
9170
9171
9172
9173
9174
9175
9176
9177
9178
9179
9180
9181
9182
9183
9184
9185
9186
9187
9188
9189
9190
9191
9192
9193
9194
9195
9196
9197
9198
9199
9200
9201
9202
9203
9204
9205
9206
9207
9208
9209
9210
9211
9212
9213
9214
9215
9216
9217
9218
9219
9220
9221
9222
9223
9224
9225
9226
9227
9228
9229
9230
9231
9232
9233
9234
9235
9236
9237
9238
9239
9240
9241
9242
9243
9244
9245
9246
9247
9248
9249
9250
9251
9252
9253
9254
9255
9256
9257
9258
9259
9260
9261
9262
9263
9264
9265
9266
9267
9268
9269
9270
9271
9272
9273
9274
9275
9276
9277
9278
9279
9280
9281
9282
9283
9284
9285
9286
9287
9288
9289
9290
9291
9292
9293
9294
9295
9296
9297
9298
9299
9300
9301
9302
9303
9304
9305
9306
9307
9308
9309
9310
9311
9312
9313
9314
9315
9316
9317
9318
9319
9320
9321
9322
9323
9324
9325
9326
9327
9328
9329
9330
9331
9332
9333
9334
9335
9336
9337
9338
9339
9340
9341
9342
9343
9344
9345
9346
9347
9348
9349
9350
9351
9352
9353
9354
9355
9356
9357
9358
9359
9360
9361
9362
9363
9364
9365
9366
9367
9368
9369
9370
9371
9372
9373
9374
9375
9376
9377
9378
9379
9380
9381
9382
9383
9384
9385
9386
9387
9388
9389
9390
9391
9392
9393
9394
9395
9396
9397
9398
9399
9400
9401
9402
9403
9404
9405
9406
9407
9408
9409
9410
9411
9412
9413
9414
9415
9416
9417
9418
9419
9420
9421
9422
9423
9424
9425
9426
9427
9428
9429
9430
9431
9432
9433
9434
9435
9436
9437
9438
9439
9440
9441
9442
9443
9444
9445
9446
9447
9448
9449
9450
9451
9452
9453
9454
9455
9456
9457
9458
9459
9460
9461
9462
9463
9464
9465
9466
9467
9468
9469
9470
9471
9472
9473
9474
9475
9476
9477
9478
9479
9480
9481
9482
9483
9484
9485
9486
9487
9488
9489
9490
9491
9492
9493
9494
9495
9496
9497
9498
9499
9500
9501
9502
9503
9504
9505
9506
9507
9508
9509
9510
9511
9512
9513
9514
9515
9516
9517
9518
9519
9520
9521
9522
9523
9524
9525
9526
9527
9528
9529
9530
9531
9532
9533
9534
9535
9536
9537
9538
9539
9540
9541
9542
9543
9544
9545
9546
9547
9548
9549
9550
9551
9552
9553
9554
9555
9556
9557
9558
9559
9560
9561
9562
9563
9564
9565
9566
9567
9568
9569
9570
9571
9572
9573
9574
9575
9576
9577
9578
9579
9580
9581
9582
9583
9584
9585
9586
9587
9588
9589
9590
9591
9592
9593
9594
9595
9596
9597
9598
9599
9600
9601
9602
9603
9604
9605
9606
9607
9608
9609
9610
9611
9612
9613
9614
9615
9616
9617
9618
9619
9620
9621
9622
9623
9624
9625
9626
9627
9628
9629
9630
9631
9632
9633
9634
9635
9636
9637
9638
9639
9640
9641
9642
9643
9644
9645
9646
9647
9648
9649
9650
9651
9652
9653
9654
9655
9656
9657
9658
9659
9660
9661
9662
9663
9664
9665
9666
9667
9668
9669
9670
9671
9672
9673
9674
9675
9676
9677
9678
9679
9680
9681
9682
9683
9684
9685
9686
9687
9688
9689
9690
9691
9692
9693
9694
9695
9696
9697
9698
9699
9700
9701
9702
9703
9704
9705
9706
9707
9708
9709
9710
9711
9712
9713
9714
9715
9716
9717
9718
9719
9720
9721
9722
9723
9724
9725
9726
9727
9728
9729
9730
9731
9732
9733
9734
9735
9736
9737
9738
9739
9740
9741
9742
9743
9744
9745
9746
9747
9748
9749
9750
9751
9752
9753
9754
9755
9756
9757
9758
9759
9760
9761
9762
9763
9764
9765
9766
9767
9768
9769
9770
9771
9772
9773
9774
9775
9776
9777
9778
9779
9780
9781
9782
9783
9784
9785
9786
9787
9788
9789
9790
9791
9792
9793
9794
9795
9796
9797
9798
9799
9800
9801
9802
9803
9804
9805
9806
9807
9808
9809
9810
9811
9812
9813
9814
9815
9816
9817
9818
9819
9820
9821
9822
9823
9824
9825
9826
9827
9828
9829
9830
9831
9832
9833
9834
9835
9836
9837
9838
9839
9840
9841
9842
9843
9844
9845
9846
9847
9848
9849
9850
9851
9852
9853
9854
9855
9856
9857
9858
9859
9860
9861
9862
9863
9864
9865
9866
9867
9868
9869
9870
9871
9872
9873
9874
9875
9876
9877
9878
9879
9880
9881
9882
9883
9884
9885
9886
9887
9888
9889
9890
9891
9892
9893
9894
9895
9896
9897
9898
9899
9900
9901
9902
9903
9904
9905
9906
9907
9908
9909
9910
9911
9912
9913
9914
9915
9916
9917
9918
9919
9920
9921
9922
9923
9924
9925
9926
9927
9928
9929
9930
9931
9932
9933
9934
9935
9936
9937
9938
9939
9940
9941
9942
9943
9944
9945
9946
9947
9948
9949
9950
9951
9952
9953
9954
9955
9956
9957
9958
9959
9960
9961
9962
9963
9964
9965
9966
9967
9968
9969
9970
9971
9972
9973
9974
9975
9976
9977
9978
9979
9980
9981
9982
9983
9984
9985
9986
9987
9988
9989
9990
9991
9992
9993
9994
9995
9996
9997
9998
9999
10000
10001
10002
10003
10004
10005
10006
10007
10008
10009
10010
10011
10012
10013
10014
10015
10016
10017
10018
10019
10020
10021
10022
10023
10024
10025
10026
10027
10028
10029
10030
10031
10032
10033
10034
10035
10036
10037
10038
10039
10040
10041
10042
10043
10044
10045
10046
10047
10048
10049
10050
10051
10052
10053
10054
10055
10056
10057
10058
10059
10060
10061
10062
10063
10064
10065
10066
10067
10068
10069
10070
10071
10072
10073
10074
10075
10076
10077
10078
10079
10080
10081
10082
10083
10084
10085
10086
10087
10088
10089
10090
10091
10092
10093
10094
10095
10096
10097
10098
10099
10100
10101
10102
10103
10104
10105
10106
10107
10108
10109
10110
10111
10112
10113
10114
10115
10116
10117
10118
10119
10120
10121
10122
10123
10124
10125
10126
10127
10128
10129
10130
10131
10132
10133
10134
10135
10136
10137
10138
10139
10140
10141
10142
10143
10144
10145
10146
10147
10148
10149
10150
10151
10152
10153
10154
10155
10156
10157
10158
10159
10160
10161
10162
10163
10164
10165
10166
10167
10168
10169
10170
10171
10172
10173
10174
10175
10176
10177
10178
10179
10180
10181
10182
10183
10184
10185
10186
10187
10188
10189
10190
10191
10192
10193
10194
10195
10196
10197
10198
10199
10200
10201
10202
10203
10204
10205
10206
10207
10208
10209
10210
10211
10212
10213
10214
10215
10216
10217
10218
10219
10220
10221
10222
10223
10224
10225
10226
10227
10228
10229
10230
10231
10232
10233
10234
10235
10236
10237
10238
10239
10240
10241
10242
10243
10244
10245
10246
10247
10248
10249
10250
10251
10252
10253
10254
10255
10256
10257
10258
10259
10260
10261
10262
10263
10264
10265
10266
10267
10268
10269
10270
10271
10272
10273
10274
10275
10276
10277
10278
10279
10280
10281
10282
10283
10284
10285
10286
10287
10288
10289
10290
10291
10292
10293
10294
10295
10296
10297
10298
10299
10300
10301
10302
10303
10304
10305
10306
10307
10308
10309
10310
10311
10312
10313
10314
10315
10316
10317
10318
10319
10320
10321
10322
10323
10324
10325
10326
10327
10328
10329
10330
10331
10332
10333
10334
10335
10336
10337
10338
10339
10340
10341
10342
10343
10344
10345
10346
10347
10348
10349
10350
10351
10352
10353
10354
10355
10356
10357
10358
10359
10360
10361
10362
10363
10364
10365
10366
10367
10368
10369
10370
10371
10372
10373
10374
10375
10376
10377
10378
10379
10380
10381
10382
10383
10384
10385
10386
10387
10388
10389
10390
10391
10392
10393
10394
10395
10396
10397
10398
10399
10400
10401
10402
10403
10404
10405
10406
10407
10408
10409
10410
10411
10412
10413
10414
10415
10416
10417
10418
10419
10420
10421
10422
10423
10424
10425
10426
10427
10428
10429
10430
10431
10432
10433
10434
10435
10436
10437
10438
10439
10440
10441
10442
10443
10444
10445
10446
10447
10448
10449
10450
10451
10452
10453
10454
10455
10456
10457
10458
10459
10460
10461
10462
10463
10464
10465
10466
10467
10468
10469
10470
10471
10472
10473
10474
10475
10476
10477
10478
10479
10480
10481
10482
10483
10484
10485
10486
10487
10488
10489
10490
10491
10492
10493
10494
10495
10496
10497
10498
10499
10500
10501
10502
10503
10504
10505
10506
10507
10508
10509
10510
10511
10512
10513
10514
10515
10516
10517
10518
10519
10520
10521
10522
10523
10524
10525
10526
10527
10528
10529
10530
10531
10532
10533
10534
10535
10536
10537
10538
10539
10540
10541
10542
10543
10544
10545
10546
10547
10548
10549
10550
10551
10552
10553
10554
10555
10556
10557
10558
10559
10560
10561
10562
10563
10564
10565
10566
10567
10568
10569
10570
10571
10572
10573
10574
10575
10576
10577
10578
10579
10580
10581
10582
10583
10584
10585
10586
10587
10588
10589
10590
10591
10592
10593
10594
10595
10596
10597
10598
10599
10600
10601
10602
10603
10604
10605
10606
10607
10608
10609
10610
10611
10612
10613
10614
10615
10616
10617
10618
10619
10620
10621
10622
10623
10624
10625
10626
10627
10628
10629
10630
10631
10632
10633
10634
10635
10636
10637
10638
10639
10640
10641
10642
10643
10644
10645
10646
10647
10648
10649
10650
10651
10652
10653
10654
10655
10656
10657
10658
10659
10660
10661
10662
10663
10664
10665
10666
10667
10668
10669
10670
10671
10672
10673
10674
10675
10676
10677
10678
10679
10680
10681
10682
10683
10684
10685
10686
10687
10688
10689
10690
10691
10692
10693
10694
10695
10696
10697
10698
10699
10700
10701
10702
10703
10704
10705
10706
10707
10708
10709
10710
10711
10712
10713
10714
10715
10716
10717
10718
10719
10720
10721
10722
10723
10724
10725
10726
10727
10728
10729
10730
10731
10732
10733
10734
10735
10736
10737
10738
10739
10740
10741
10742
10743
10744
10745
10746
10747
10748
10749
10750
10751
10752
10753
10754
10755
10756
10757
10758
10759
10760
10761
10762
10763
10764
10765
10766
10767
10768
10769
10770
10771
10772
10773
10774
10775
10776
10777
10778
10779
10780
10781
10782
10783
10784
10785
10786
10787
10788
10789
10790
10791
10792
10793
10794
10795
10796
10797
10798
10799
10800
10801
10802
10803
10804
10805
10806
10807
10808
10809
10810
10811
10812
10813
10814
10815
10816
10817
10818
10819
10820
10821
10822
10823
10824
10825
10826
10827
10828
10829
10830
10831
10832
10833
10834
10835
10836
10837
10838
10839
10840
10841
10842
10843
10844
10845
10846
10847
10848
10849
10850
10851
10852
10853
10854
10855
10856
10857
10858
10859
10860
10861
10862
10863
10864
10865
10866
10867
10868
10869
10870
10871
10872
10873
10874
10875
10876
10877
10878
10879
10880
10881
10882
10883
10884
10885
10886
10887
10888
10889
10890
10891
10892
10893
10894
10895
10896
10897
10898
10899
10900
10901
10902
10903
10904
10905
10906
10907
10908
10909
10910
10911
10912
10913
10914
10915
10916
10917
10918
10919
10920
10921
10922
10923
10924
10925
10926
10927
10928
10929
10930
10931
10932
10933
10934
10935
10936
10937
10938
10939
10940
10941
10942
10943
10944
10945
10946
10947
10948
10949
10950
10951
10952
10953
10954
10955
10956
10957
10958
10959
10960
10961
10962
10963
10964
10965
10966
10967
10968
10969
10970
10971
10972
10973
10974
10975
10976
10977
10978
10979
10980
10981
10982
10983
10984
10985
10986
10987
10988
10989
10990
10991
10992
10993
10994
10995
10996
10997
10998
10999
11000
11001
11002
11003
11004
11005
11006
11007
11008
11009
11010
11011
11012
11013
11014
11015
11016
11017
11018
11019
11020
11021
11022
11023
11024
11025
11026
11027
11028
11029
11030
11031
11032
11033
11034
11035
11036
11037
11038
11039
11040
11041
11042
11043
11044
11045
11046
11047
11048
11049
11050
11051
11052
11053
11054
11055
11056
11057
11058
11059
11060
11061
11062
11063
11064
11065
11066
11067
11068
11069
11070
11071
11072
11073
11074
11075
11076
11077
11078
11079
11080
11081
11082
11083
11084
11085
11086
11087
11088
11089
11090
11091
11092
11093
11094
11095
11096
11097
11098
11099
11100
11101
11102
11103
11104
11105
11106
11107
11108
11109
11110
11111
11112
11113
11114
11115
11116
11117
11118
11119
11120
11121
11122
11123
11124
11125
11126
11127
11128
11129
11130
11131
11132
11133
11134
11135
11136
11137
11138
11139
11140
11141
11142
11143
11144
11145
11146
11147
11148
11149
11150
11151
11152
11153
11154
11155
11156
11157
11158
11159
11160
11161
11162
11163
11164
11165
11166
11167
11168
11169
11170
11171
11172
11173
11174
11175
11176
11177
11178
11179
11180
11181
11182
11183
11184
11185
11186
11187
11188
11189
11190
11191
11192
11193
11194
11195
11196
11197
11198
11199
11200
11201
11202
11203
11204
11205
11206
11207
11208
11209
11210
11211
11212
11213
11214
11215
11216
11217
11218
11219
11220
11221
11222
11223
11224
11225
11226
11227
11228
11229
11230
11231
11232
11233
11234
11235
11236
11237
11238
11239
11240
11241
11242
11243
11244
11245
11246
11247
11248
11249
11250
11251
11252
11253
11254
11255
11256
11257
11258
11259
11260
11261
11262
11263
11264
11265
11266
11267
11268
11269
11270
11271
11272
11273
11274
11275
11276
11277
11278
11279
11280
11281
11282
11283
11284
11285
11286
11287
11288
11289
11290
11291
11292
11293
11294
11295
11296
11297
11298
11299
11300
11301
11302
11303
11304
11305
11306
11307
11308
11309
11310
11311
11312
11313
11314
11315
11316
11317
11318
11319
11320
11321
11322
11323
11324
11325
11326
11327
11328
11329
11330
11331
11332
11333
11334
11335
11336
11337
11338
11339
11340
11341
11342
11343
11344
11345
11346
11347
11348
11349
11350
11351
11352
11353
11354
11355
11356
11357
11358
11359
11360
11361
11362
11363
11364
11365
11366
11367
11368
11369
11370
11371
11372
11373
11374
11375
11376
11377
11378
11379
11380
11381
11382
11383
11384
11385
11386
11387
11388
11389
11390
11391
11392
11393
11394
11395
11396
11397
11398
11399
11400
11401
11402
11403
11404
11405
11406
11407
11408
11409
11410
11411
11412
11413
11414
11415
11416
11417
11418
11419
11420
11421
11422
11423
11424
11425
11426
11427
11428
11429
11430
11431
11432
11433
11434
11435
11436
11437
11438
11439
11440
11441
11442
11443
11444
11445
11446
11447
11448
11449
11450
11451
11452
11453
11454
11455
11456
11457
11458
11459
11460
11461
11462
11463
11464
11465
11466
11467
11468
11469
11470
11471
11472
11473
11474
11475
11476
11477
11478
11479
11480
11481
11482
11483
11484
11485
11486
11487
11488
11489
11490
11491
11492
11493
11494
11495
11496
11497
11498
11499
11500
11501
11502
11503
11504
11505
11506
11507
11508
11509
11510
11511
11512
11513
11514
11515
11516
11517
11518
11519
11520
11521
11522
11523
11524
11525
11526
11527
11528
11529
11530
11531
11532
11533
11534
11535
11536
11537
11538
11539
11540
11541
11542
11543
11544
11545
11546
11547
11548
11549
11550
11551
11552
11553
11554
11555
11556
11557
11558
11559
11560
11561
11562
11563
11564
11565
11566
11567
11568
11569
11570
11571
11572
11573
11574
11575
11576
11577
11578
11579
11580
11581
11582
11583
11584
11585
11586
11587
11588
11589
11590
11591
11592
11593
11594
11595
11596
11597
11598
11599
11600
11601
11602
11603
11604
11605
11606
11607
11608
11609
11610
11611
11612
11613
11614
11615
11616
11617
11618
11619
11620
11621
11622
11623
11624
11625
11626
11627
11628
11629
11630
11631
11632
11633
11634
11635
11636
11637
11638
11639
11640
11641
11642
11643
11644
11645
11646
11647
11648
11649
11650
11651
11652
11653
11654
11655
11656
11657
11658
11659
11660
11661
11662
11663
11664
11665
11666
11667
11668
11669
11670
11671
11672
11673
11674
11675
11676
11677
11678
11679
11680
11681
11682
11683
11684
11685
11686
11687
11688
11689
11690
11691
11692
11693
11694
11695
11696
11697
11698
11699
11700
11701
11702
11703
11704
11705
11706
11707
11708
11709
11710
11711
11712
11713
11714
11715
11716
11717
11718
11719
11720
11721
11722
11723
11724
11725
11726
11727
11728
11729
11730
11731
11732
11733
11734
11735
11736
11737
11738
11739
11740
11741
11742
11743
11744
11745
11746
11747
11748
11749
11750
11751
11752
11753
11754
11755
11756
11757
11758
11759
11760
11761
11762
11763
11764
11765
11766
11767
11768
11769
11770
11771
11772
11773
11774
11775
11776
11777
11778
11779
11780
11781
11782
11783
11784
11785
11786
11787
11788
11789
11790
11791
11792
11793
11794
11795
11796
11797
11798
11799
11800
11801
11802
11803
11804
11805
11806
11807
11808
11809
11810
11811
11812
11813
11814
11815
11816
11817
11818
11819
11820
11821
11822
11823
11824
11825
11826
11827
11828
11829
11830
11831
11832
11833
11834
11835
11836
11837
11838
11839
11840
11841
11842
11843
11844
11845
11846
11847
11848
11849
11850
11851
11852
11853
11854
11855
11856
11857
11858
11859
11860
11861
11862
11863
11864
11865
11866
11867
11868
11869
11870
11871
11872
11873
11874
11875
11876
11877
11878
11879
11880
11881
11882
11883
11884
11885
11886
11887
11888
11889
11890
11891
11892
11893
11894
11895
11896
11897
11898
11899
11900
11901
11902
11903
11904
11905
11906
11907
11908
11909
11910
11911
11912
11913
11914
11915
11916
11917
11918
11919
11920
11921
11922
11923
11924
11925
11926
11927
11928
11929
11930
11931
11932
11933
11934
11935
11936
11937
11938
11939
11940
11941
11942
11943
11944
11945
11946
11947
11948
11949
11950
11951
11952
11953
11954
11955
11956
11957
11958
11959
11960
11961
11962
11963
11964
11965
11966
11967
11968
11969
11970
11971
11972
11973
11974
11975
11976
11977
11978
11979
11980
11981
11982
11983
11984
11985
11986
11987
11988
11989
11990
11991
11992
11993
11994
11995
11996
11997
11998
11999
12000
12001
12002
12003
12004
12005
12006
12007
12008
12009
12010
12011
12012
12013
12014
12015
12016
12017
12018
12019
12020
12021
12022
12023
12024
12025
12026
12027
12028
12029
12030
12031
12032
12033
12034
12035
12036
12037
12038
12039
12040
12041
12042
12043
12044
12045
12046
12047
12048
12049
12050
12051
12052
12053
12054
12055
12056
12057
12058
12059
12060
12061
12062
12063
12064
12065
12066
12067
12068
12069
12070
12071
12072
12073
12074
12075
12076
12077
12078
12079
12080
12081
12082
12083
12084
12085
12086
12087
12088
12089
12090
12091
12092
12093
12094
12095
12096
12097
12098
12099
12100
12101
12102
12103
12104
12105
12106
12107
12108
12109
12110
12111
12112
12113
12114
12115
12116
12117
12118
12119
12120
12121
12122
12123
12124
12125
12126
12127
12128
12129
12130
12131
12132
12133
12134
12135
12136
12137
12138
12139
12140
12141
12142
12143
12144
12145
12146
12147
12148
12149
12150
12151
12152
12153
12154
12155
12156
12157
12158
12159
12160
12161
12162
12163
12164
12165
12166
12167
12168
12169
12170
12171
12172
12173
12174
12175
12176
12177
12178
12179
12180
12181
12182
12183
12184
12185
12186
12187
12188
12189
12190
12191
12192
12193
12194
12195
12196
12197
12198
12199
12200
12201
12202
12203
12204
12205
12206
12207
12208
12209
12210
12211
12212
12213
12214
12215
12216
12217
12218
12219
12220
12221
12222
12223
12224
12225
12226
12227
12228
12229
12230
12231
12232
12233
12234
12235
12236
12237
12238
12239
12240
12241
12242
12243
12244
12245
12246
12247
12248
12249
12250
12251
12252
12253
12254
12255
12256
12257
12258
12259
12260
12261
12262
12263
12264
12265
12266
12267
12268
12269
12270
12271
12272
12273
12274
12275
12276
12277
12278
12279
12280
12281
12282
12283
12284
12285
12286
12287
12288
12289
12290
12291
12292
12293
12294
12295
12296
12297
12298
12299
12300
12301
12302
12303
12304
12305
12306
12307
12308
12309
12310
12311
12312
12313
12314
12315
12316
12317
12318
12319
12320
12321
12322
12323
12324
12325
12326
12327
12328
12329
12330
12331
12332
12333
12334
12335
12336
12337
12338
12339
12340
12341
12342
12343
12344
12345
12346
12347
12348
12349
12350
12351
12352
12353
12354
12355
12356
12357
12358
12359
12360
12361
12362
12363
12364
12365
12366
12367
12368
12369
12370
12371
12372
12373
12374
12375
12376
12377
12378
12379
12380
12381
12382
12383
12384
12385
12386
12387
12388
12389
12390
12391
12392
12393
12394
12395
12396
12397
12398
12399
12400
12401
12402
12403
12404
12405
12406
12407
12408
12409
12410
12411
12412
12413
12414
12415
12416
12417
12418
12419
12420
12421
12422
12423
12424
12425
12426
12427
12428
12429
12430
12431
12432
12433
12434
12435
12436
12437
12438
12439
12440
12441
12442
12443
12444
12445
12446
12447
12448
12449
12450
12451
12452
12453
12454
12455
12456
12457
12458
12459
12460
12461
12462
12463
12464
12465
12466
12467
12468
12469
12470
12471
12472
12473
12474
12475
12476
12477
12478
12479
12480
12481
12482
12483
12484
12485
12486
12487
12488
12489
12490
12491
12492
12493
12494
12495
12496
12497
12498
12499
12500
12501
12502
12503
12504
12505
12506
12507
12508
12509
12510
12511
12512
12513
12514
12515
12516
12517
12518
12519
12520
12521
12522
12523
12524
12525
12526
12527
12528
12529
12530
12531
12532
12533
12534
12535
12536
12537
12538
12539
12540
12541
12542
12543
12544
12545
12546
12547
12548
12549
12550
12551
12552
12553
12554
12555
12556
12557
12558
12559
12560
12561
12562
12563
12564
12565
12566
12567
12568
12569
12570
12571
12572
12573
12574
12575
12576
12577
12578
12579
12580
12581
12582
12583
12584
12585
12586
12587
12588
12589
12590
12591
12592
12593
12594
12595
12596
12597
12598
12599
12600
12601
12602
12603
12604
12605
12606
12607
12608
12609
12610
12611
12612
12613
12614
12615
12616
12617
12618
12619
12620
12621
12622
12623
12624
12625
12626
12627
12628
12629
12630
12631
12632
12633
12634
12635
12636
12637
12638
12639
12640
12641
12642
12643
12644
12645
12646
12647
12648
12649
12650
12651
12652
12653
12654
12655
12656
12657
12658
12659
12660
12661
12662
12663
12664
12665
12666
12667
12668
12669
12670
12671
12672
12673
12674
12675
12676
12677
12678
12679
12680
12681
12682
12683
12684
12685
12686
12687
12688
12689
12690
12691
12692
12693
12694
12695
12696
12697
12698
12699
12700
12701
12702
12703
12704
12705
12706
12707
12708
12709
12710
12711
12712
12713
12714
12715
12716
12717
12718
12719
12720
12721
12722
12723
12724
12725
12726
12727
12728
12729
12730
12731
12732
12733
12734
12735
12736
12737
12738
12739
12740
12741
12742
12743
12744
12745
12746
12747
12748
12749
12750
12751
12752
12753
12754
12755
12756
12757
12758
12759
12760
12761
12762
12763
12764
12765
12766
12767
12768
12769
12770
12771
12772
12773
12774
12775
12776
12777
12778
12779
12780
12781
12782
12783
12784
12785
12786
12787
12788
12789
12790
12791
12792
12793
12794
12795
12796
12797
12798
12799
12800
12801
12802
12803
12804
12805
12806
12807
12808
12809
12810
12811
12812
12813
12814
12815
12816
12817
12818
12819
12820
12821
12822
12823
12824
12825
12826
12827
12828
12829
12830
12831
12832
12833
12834
12835
12836
12837
12838
12839
12840
12841
12842
12843
12844
12845
12846
12847
12848
12849
12850
12851
12852
12853
12854
12855
12856
12857
12858
12859
12860
12861
12862
12863
12864
12865
12866
12867
12868
12869
12870
12871
12872
12873
12874
12875
12876
12877
12878
12879
12880
12881
12882
12883
12884
12885
12886
12887
12888
12889
12890
12891
12892
12893
12894
12895
12896
12897
12898
12899
12900
12901
12902
12903
12904
12905
12906
12907
12908
12909
12910
12911
12912
12913
12914
12915
12916
12917
12918
12919
12920
12921
12922
12923
12924
12925
12926
12927
12928
12929
12930
12931
12932
12933
12934
12935
12936
12937
12938
12939
12940
12941
12942
12943
12944
12945
12946
12947
12948
12949
12950
12951
12952
12953
12954
12955
12956
12957
12958
12959
12960
12961
12962
12963
12964
12965
12966
12967
12968
12969
12970
12971
12972
12973
12974
12975
12976
12977
12978
12979
12980
12981
12982
12983
12984
12985
12986
12987
12988
12989
12990
12991
/* vi: set sw=4 ts=4: */
/*
 * ash shell port for busybox
 *
 * Copyright (c) 1989, 1991, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
 * was re-ported from NetBSD and debianized.
 *
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 *
 * Original BSD copyright notice is retained at the end of this file.
 */

/*
 * rewrite arith.y to micro stack based cryptic algorithm by
 * Copyright (c) 2001 Aaron Lehmann <aaronl@vitelus.com>
 *
 * Modified by Paul Mundt <lethal@linux-sh.org> (c) 2004 to support
 * dynamic variables.
 *
 * Modified by Vladimir Oleynik <dzo@simtreas.ru> (c) 2001-2005 to be
 * used in busybox and size optimizations,
 * rewrote arith (see notes to this), added locale support,
 * rewrote dynamic variables.
 *
 */

/*
 * The follow should be set to reflect the type of system you have:
 *      JOBS -> 1 if you have Berkeley job control, 0 otherwise.
 *      define SYSV if you are running under System V.
 *      define DEBUG=1 to compile in debugging ('set -o debug' to turn on)
 *      define DEBUG=2 to compile in and turn on debugging.
 *
 * When debugging is on, debugging info will be written to ./trace and
 * a quit signal will generate a core dump.
 */
#define DEBUG 0
#define IFS_BROKEN
#define PROFILE 0
#if ENABLE_ASH_JOB_CONTROL
#define JOBS 1
#else
#define JOBS 0
#endif

#if DEBUG
#define _GNU_SOURCE
#endif
#include "busybox.h"
#include <paths.h>
#include <setjmp.h>
#include <fnmatch.h>
#if JOBS || ENABLE_ASH_READ_NCHARS
#include <termios.h>
#endif

#if defined(__uClinux__)
#error "Do not even bother, ash will not run on uClinux"
#endif


/* ============ Misc helpers */

#define xbarrier() do { __asm__ __volatile__ ("": : :"memory"); } while (0)

/* C99 say: "char" declaration may be signed or unsigned default */
#define signed_char2int(sc) ((int)((signed char)sc))


/* ============ Shell options */

static const char *const optletters_optnames[] = {
	"e"   "errexit",
	"f"   "noglob",
	"I"   "ignoreeof",
	"i"   "interactive",
	"m"   "monitor",
	"n"   "noexec",
	"s"   "stdin",
	"x"   "xtrace",
	"v"   "verbose",
	"C"   "noclobber",
	"a"   "allexport",
	"b"   "notify",
	"u"   "nounset",
	"\0"  "vi",
#if DEBUG
	"\0"  "nolog",
	"\0"  "debug",
#endif
};

#define optletters(n) optletters_optnames[(n)][0]
#define optnames(n) (&optletters_optnames[(n)][1])

#define NOPTS (sizeof(optletters_optnames)/sizeof(optletters_optnames[0]))

static char optlist[NOPTS];

#define eflag optlist[0]
#define fflag optlist[1]
#define Iflag optlist[2]
#define iflag optlist[3]
#define mflag optlist[4]
#define nflag optlist[5]
#define sflag optlist[6]
#define xflag optlist[7]
#define vflag optlist[8]
#define Cflag optlist[9]
#define aflag optlist[10]
#define bflag optlist[11]
#define uflag optlist[12]
#define viflag optlist[13]
#if DEBUG
#define nolog optlist[14]
#define debug optlist[15]
#endif


/* ============ Misc data */

#ifdef __GLIBC__
/* glibc sucks */
static int *dash_errno;
#undef errno
#define errno (*dash_errno)
#endif

static char nullstr[1];                /* zero length string */
static const char homestr[] = "HOME";
static const char snlfmt[] = "%s\n";
static const char illnum[] = "Illegal number: %s";

static char *minusc;                   /* argument to -c option */

static int isloginsh;
/* pid of main shell */
static int rootpid;
/* shell level: 0 for the main shell, 1 for its children, and so on */
static int shlvl;
#define rootshell (!shlvl)
/* trap handler commands */
static char *trap[NSIG];
/* current value of signal */
static char sigmode[NSIG - 1];
/* indicates specified signal received */
static char gotsig[NSIG - 1];
static char *arg0; /* value of $0 */


/* ============ Interrupts / exceptions */

/*
 * We enclose jmp_buf in a structure so that we can declare pointers to
 * jump locations.  The global variable handler contains the location to
 * jump to when an exception occurs, and the global variable exception
 * contains a code identifying the exception.  To implement nested
 * exception handlers, the user should save the value of handler on entry
 * to an inner scope, set handler to point to a jmploc structure for the
 * inner scope, and restore handler on exit from the scope.
 */
struct jmploc {
	jmp_buf loc;
};
static struct jmploc *exception_handler;
static int exception;
/* exceptions */
#define EXINT 0         /* SIGINT received */
#define EXERROR 1       /* a generic error */
#define EXSHELLPROC 2   /* execute a shell procedure */
#define EXEXEC 3        /* command execution failed */
#define EXEXIT 4        /* exit the shell */
#define EXSIG 5         /* trapped signal in wait(1) */
static volatile int suppressint;
static volatile sig_atomic_t intpending;
/* do we generate EXSIG events */
static int exsig;
/* last pending signal */
static volatile sig_atomic_t pendingsigs;

/*
 * Sigmode records the current value of the signal handlers for the various
 * modes.  A value of zero means that the current handler is not known.
 * S_HARD_IGN indicates that the signal was ignored on entry to the shell,
 */

#define S_DFL 1                 /* default signal handling (SIG_DFL) */
#define S_CATCH 2               /* signal is caught */
#define S_IGN 3                 /* signal is ignored (SIG_IGN) */
#define S_HARD_IGN 4            /* signal is ignored permenantly */
#define S_RESET 5               /* temporary - to reset a hard ignored sig */

/*
 * These macros allow the user to suspend the handling of interrupt signals
 * over a period of time.  This is similar to SIGHOLD to or sigblock, but
 * much more efficient and portable.  (But hacking the kernel is so much
 * more fun than worrying about efficiency and portability. :-))
 */
#define INT_OFF \
	do { \
		suppressint++; \
		xbarrier(); \
	} while (0)

/*
 * Called to raise an exception.  Since C doesn't include exceptions, we
 * just do a longjmp to the exception handler.  The type of exception is
 * stored in the global variable "exception".
 */
static void raise_exception(int) ATTRIBUTE_NORETURN;
static void
raise_exception(int e)
{
#if DEBUG
	if (exception_handler == NULL)
		abort();
#endif
	INT_OFF;
	exception = e;
	longjmp(exception_handler->loc, 1);
}

/*
 * Called from trap.c when a SIGINT is received.  (If the user specifies
 * that SIGINT is to be trapped or ignored using the trap builtin, then
 * this routine is not called.)  Suppressint is nonzero when interrupts
 * are held using the INT_OFF macro.  (The test for iflag is just
 * defensive programming.)
 */
static void raise_interrupt(void) ATTRIBUTE_NORETURN;
static void
raise_interrupt(void)
{
	int i;

	intpending = 0;
	i = EXSIG;
	if (gotsig[SIGINT - 1] && !trap[SIGINT]) {
		if (!(rootshell && iflag)) {
			signal(SIGINT, SIG_DFL);
			raise(SIGINT);
		}
		i = EXINT;
	}
	raise_exception(i);
	/* NOTREACHED */
}

#if ENABLE_ASH_OPTIMIZE_FOR_SIZE
static void
int_on(void)
{
	if (--suppressint == 0 && intpending) {
		raise_interrupt();
	}
}
#define INT_ON int_on()
static void
force_int_on(void)
{
	suppressint = 0;
	if (intpending)
		raise_interrupt();
}
#define FORCE_INT_ON force_int_on()
#else
#define INT_ON \
	do { \
		xbarrier(); \
		if (--suppressint == 0 && intpending) \
			raise_interrupt(); \
	} while (0)
#define FORCE_INT_ON \
	do { \
		xbarrier(); \
		suppressint = 0; \
		if (intpending) \
			raise_interrupt(); \
	} while (0)
#endif /* ASH_OPTIMIZE_FOR_SIZE */

#define SAVE_INT(v) ((v) = suppressint)

#define RESTORE_INT(v) \
	do { \
		xbarrier(); \
		suppressint = (v); \
		if (suppressint == 0 && intpending) \
			raise_interrupt(); \
	} while (0)

#define EXSIGON \
	do { \
		exsig++; \
		xbarrier(); \
		if (pendingsigs) \
			raise_exception(EXSIG); \
	} while (0)
/* EXSIG is turned off by evalbltin(). */

/*
 * Ignore a signal. Only one usage site - in forkchild()
 */
static void
ignoresig(int signo)
{
	if (sigmode[signo - 1] != S_IGN && sigmode[signo - 1] != S_HARD_IGN) {
		signal(signo, SIG_IGN);
	}
	sigmode[signo - 1] = S_HARD_IGN;
}

/*
 * Signal handler. Only one usage site - in setsignal()
 */
static void
onsig(int signo)
{
	gotsig[signo - 1] = 1;
	pendingsigs = signo;

	if (exsig || (signo == SIGINT && !trap[SIGINT])) {
		if (!suppressint)
			raise_interrupt();
		intpending = 1;
	}
}


/* ============ Stdout/stderr output */

static void
outstr(const char *p, FILE *file)
{
	INT_OFF;
	fputs(p, file);
	INT_ON;
}

static void
flush_stdout_stderr(void)
{
	INT_OFF;
	fflush(stdout);
	fflush(stderr);
	INT_ON;
}

static void
flush_stderr(void)
{
	INT_OFF;
	fflush(stderr);
	INT_ON;
}

static void
outcslow(int c, FILE *dest)
{
	INT_OFF;
	putc(c, dest);
	fflush(dest);
	INT_ON;
}

static int out1fmt(const char *, ...) __attribute__((__format__(__printf__,1,2)));
static int
out1fmt(const char *fmt, ...)
{
	va_list ap;
	int r;

	INT_OFF;
	va_start(ap, fmt);
	r = vprintf(fmt, ap);
	va_end(ap);
	INT_ON;
	return r;
}

static int fmtstr(char *, size_t, const char *, ...) __attribute__((__format__(__printf__,3,4)));
static int
fmtstr(char *outbuf, size_t length, const char *fmt, ...)
{
	va_list ap;
	int ret;

	va_start(ap, fmt);
	INT_OFF;
	ret = vsnprintf(outbuf, length, fmt, ap);
	va_end(ap);
	INT_ON;
	return ret;
}

static void
out1str(const char *p)
{
	outstr(p, stdout);
}

static void
out2str(const char *p)
{
	outstr(p, stderr);
	flush_stderr();
}


/* ============ Parser structures */

/* control characters in argument strings */
#define CTLESC '\201'           /* escape next character */
#define CTLVAR '\202'           /* variable defn */
#define CTLENDVAR '\203'
#define CTLBACKQ '\204'
#define CTLQUOTE 01             /* ored with CTLBACKQ code if in quotes */
/*      CTLBACKQ | CTLQUOTE == '\205' */
#define CTLARI  '\206'          /* arithmetic expression */
#define CTLENDARI '\207'
#define CTLQUOTEMARK '\210'

/* variable substitution byte (follows CTLVAR) */
#define VSTYPE  0x0f            /* type of variable substitution */
#define VSNUL   0x10            /* colon--treat the empty string as unset */
#define VSQUOTE 0x80            /* inside double quotes--suppress splitting */

/* values of VSTYPE field */
#define VSNORMAL        0x1             /* normal variable:  $var or ${var} */
#define VSMINUS         0x2             /* ${var-text} */
#define VSPLUS          0x3             /* ${var+text} */
#define VSQUESTION      0x4             /* ${var?message} */
#define VSASSIGN        0x5             /* ${var=text} */
#define VSTRIMRIGHT     0x6             /* ${var%pattern} */
#define VSTRIMRIGHTMAX  0x7             /* ${var%%pattern} */
#define VSTRIMLEFT      0x8             /* ${var#pattern} */
#define VSTRIMLEFTMAX   0x9             /* ${var##pattern} */
#define VSLENGTH        0xa             /* ${#var} */

static const char dolatstr[] = { CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0' };

#define NCMD 0
#define NPIPE 1
#define NREDIR 2
#define NBACKGND 3
#define NSUBSHELL 4
#define NAND 5
#define NOR 6
#define NSEMI 7
#define NIF 8
#define NWHILE 9
#define NUNTIL 10
#define NFOR 11
#define NCASE 12
#define NCLIST 13
#define NDEFUN 14
#define NARG 15
#define NTO 16
#define NCLOBBER 17
#define NFROM 18
#define NFROMTO 19
#define NAPPEND 20
#define NTOFD 21
#define NFROMFD 22
#define NHERE 23
#define NXHERE 24
#define NNOT 25

union node;

struct ncmd {
	int type;
	union node *assign;
	union node *args;
	union node *redirect;
};

struct npipe {
	int type;
	int backgnd;
	struct nodelist *cmdlist;
};

struct nredir {
	int type;
	union node *n;
	union node *redirect;
};

struct nbinary {
	int type;
	union node *ch1;
	union node *ch2;
};

struct nif {
	int type;
	union node *test;
	union node *ifpart;
	union node *elsepart;
};

struct nfor {
	int type;
	union node *args;
	union node *body;
	char *var;
};

struct ncase {
	int type;
	union node *expr;
	union node *cases;
};

struct nclist {
	int type;
	union node *next;
	union node *pattern;
	union node *body;
};

struct narg {
	int type;
	union node *next;
	char *text;
	struct nodelist *backquote;
};

struct nfile {
	int type;
	union node *next;
	int fd;
	union node *fname;
	char *expfname;
};

struct ndup {
	int type;
	union node *next;
	int fd;
	int dupfd;
	union node *vname;
};

struct nhere {
	int type;
	union node *next;
	int fd;
	union node *doc;
};

struct nnot {
	int type;
	union node *com;
};

union node {
	int type;
	struct ncmd ncmd;
	struct npipe npipe;
	struct nredir nredir;
	struct nbinary nbinary;
	struct nif nif;
	struct nfor nfor;
	struct ncase ncase;
	struct nclist nclist;
	struct narg narg;
	struct nfile nfile;
	struct ndup ndup;
	struct nhere nhere;
	struct nnot nnot;
};

struct nodelist {
	struct nodelist *next;
	union node *n;
};

struct funcnode {
	int count;
	union node n;
};

/*
 * Free a parse tree.
 */
static void
freefunc(struct funcnode *f)
{
	if (f && --f->count < 0)
		free(f);
}


/* ============ Debugging output */

#if DEBUG

static FILE *tracefile;

static void
trace_printf(const char *fmt, ...)
{
	va_list va;

	if (debug != 1)
		return;
	va_start(va, fmt);
	vfprintf(tracefile, fmt, va);
	va_end(va);
}

static void
trace_vprintf(const char *fmt, va_list va)
{
	if (debug != 1)
		return;
	vfprintf(tracefile, fmt, va);
}

static void
trace_puts(const char *s)
{
	if (debug != 1)
		return;
	fputs(s, tracefile);
}

static void
trace_puts_quoted(char *s)
{
	char *p;
	char c;

	if (debug != 1)
		return;
	putc('"', tracefile);
	for (p = s; *p; p++) {
		switch (*p) {
		case '\n':  c = 'n';  goto backslash;
		case '\t':  c = 't';  goto backslash;
		case '\r':  c = 'r';  goto backslash;
		case '"':  c = '"';  goto backslash;
		case '\\':  c = '\\';  goto backslash;
		case CTLESC:  c = 'e';  goto backslash;
		case CTLVAR:  c = 'v';  goto backslash;
		case CTLVAR+CTLQUOTE:  c = 'V'; goto backslash;
		case CTLBACKQ:  c = 'q';  goto backslash;
		case CTLBACKQ+CTLQUOTE:  c = 'Q'; goto backslash;
 backslash:
			putc('\\', tracefile);
			putc(c, tracefile);
			break;
		default:
			if (*p >= ' ' && *p <= '~')
				putc(*p, tracefile);
			else {
				putc('\\', tracefile);
				putc(*p >> 6 & 03, tracefile);
				putc(*p >> 3 & 07, tracefile);
				putc(*p & 07, tracefile);
			}
			break;
		}
	}
	putc('"', tracefile);
}

static void
trace_puts_args(char **ap)
{
	if (debug != 1)
		return;
	if (!*ap)
		return;
	while (1) {
		trace_puts_quoted(*ap);
		if (!*++ap) {
			putc('\n', tracefile);
			break;
		}
		putc(' ', tracefile);
	}
}

static void
opentrace(void)
{
	char s[100];
#ifdef O_APPEND
	int flags;
#endif

	if (debug != 1) {
		if (tracefile)
			fflush(tracefile);
		/* leave open because libedit might be using it */
		return;
	}
	strcpy(s, "./trace");
	if (tracefile) {
		if (!freopen(s, "a", tracefile)) {
			fprintf(stderr, "Can't re-open %s\n", s);
			debug = 0;
			return;
		}
	} else {
		tracefile = fopen(s, "a");
		if (tracefile == NULL) {
			fprintf(stderr, "Can't open %s\n", s);
			debug = 0;
			return;
		}
	}
#ifdef O_APPEND
	flags = fcntl(fileno(tracefile), F_GETFL, 0);
	if (flags >= 0)
		fcntl(fileno(tracefile), F_SETFL, flags | O_APPEND);
#endif
	setlinebuf(tracefile);
	fputs("\nTracing started.\n", tracefile);
}

static void
indent(int amount, char *pfx, FILE *fp)
{
	int i;

	for (i = 0; i < amount; i++) {
		if (pfx && i == amount - 1)
			fputs(pfx, fp);
		putc('\t', fp);
	}
}

/* little circular references here... */
static void shtree(union node *n, int ind, char *pfx, FILE *fp);

static void
sharg(union node *arg, FILE *fp)
{
	char *p;
	struct nodelist *bqlist;
	int subtype;

	if (arg->type != NARG) {
		out1fmt("<node type %d>\n", arg->type);
		abort();
	}
	bqlist = arg->narg.backquote;
	for (p = arg->narg.text; *p; p++) {
		switch (*p) {
		case CTLESC:
			putc(*++p, fp);
			break;
		case CTLVAR:
			putc('$', fp);
			putc('{', fp);
			subtype = *++p;
			if (subtype == VSLENGTH)
				putc('#', fp);

			while (*p != '=')
				putc(*p++, fp);

			if (subtype & VSNUL)
				putc(':', fp);

			switch (subtype & VSTYPE) {
			case VSNORMAL:
				putc('}', fp);
				break;
			case VSMINUS:
				putc('-', fp);
				break;
			case VSPLUS:
				putc('+', fp);
				break;
			case VSQUESTION:
				putc('?', fp);
				break;
			case VSASSIGN:
				putc('=', fp);
				break;
			case VSTRIMLEFT:
				putc('#', fp);
				break;
			case VSTRIMLEFTMAX:
				putc('#', fp);
				putc('#', fp);
				break;
			case VSTRIMRIGHT:
				putc('%', fp);
				break;
			case VSTRIMRIGHTMAX:
				putc('%', fp);
				putc('%', fp);
				break;
			case VSLENGTH:
				break;
			default:
				out1fmt("<subtype %d>", subtype);
			}
			break;
		case CTLENDVAR:
			putc('}', fp);
			break;
		case CTLBACKQ:
		case CTLBACKQ|CTLQUOTE:
			putc('$', fp);
			putc('(', fp);
			shtree(bqlist->n, -1, NULL, fp);
			putc(')', fp);
			break;
		default:
			putc(*p, fp);
			break;
		}
	}
}

static void
shcmd(union node *cmd, FILE *fp)
{
	union node *np;
	int first;
	const char *s;
	int dftfd;

	first = 1;
	for (np = cmd->ncmd.args; np; np = np->narg.next) {
		if (! first)
			putchar(' ');
		sharg(np, fp);
		first = 0;
	}
	for (np = cmd->ncmd.redirect; np; np = np->nfile.next) {
		if (! first)
			putchar(' ');
		switch (np->nfile.type) {
		case NTO:       s = ">";  dftfd = 1; break;
		case NCLOBBER:  s = ">|"; dftfd = 1; break;
		case NAPPEND:   s = ">>"; dftfd = 1; break;
		case NTOFD:     s = ">&"; dftfd = 1; break;
		case NFROM:     s = "<";  dftfd = 0; break;
		case NFROMFD:   s = "<&"; dftfd = 0; break;
		case NFROMTO:   s = "<>"; dftfd = 0; break;
		default:        s = "*error*"; dftfd = 0; break;
		}
		if (np->nfile.fd != dftfd)
			fprintf(fp, "%d", np->nfile.fd);
		fputs(s, fp);
		if (np->nfile.type == NTOFD || np->nfile.type == NFROMFD) {
			fprintf(fp, "%d", np->ndup.dupfd);
		} else {
			sharg(np->nfile.fname, fp);
		}
		first = 0;
	}
}

static void
shtree(union node *n, int ind, char *pfx, FILE *fp)
{
	struct nodelist *lp;
	const char *s;

	if (n == NULL)
		return;

	indent(ind, pfx, fp);
	switch (n->type) {
	case NSEMI:
		s = "; ";
		goto binop;
	case NAND:
		s = " && ";
		goto binop;
	case NOR:
		s = " || ";
 binop:
		shtree(n->nbinary.ch1, ind, NULL, fp);
		/* if (ind < 0) */
			fputs(s, fp);
		shtree(n->nbinary.ch2, ind, NULL, fp);
		break;
	case NCMD:
		shcmd(n, fp);
		if (ind >= 0)
			putc('\n', fp);
		break;
	case NPIPE:
		for (lp = n->npipe.cmdlist; lp; lp = lp->next) {
			shcmd(lp->n, fp);
			if (lp->next)
				fputs(" | ", fp);
		}
		if (n->npipe.backgnd)
			fputs(" &", fp);
		if (ind >= 0)
			putc('\n', fp);
		break;
	default:
		fprintf(fp, "<node type %d>", n->type);
		if (ind >= 0)
			putc('\n', fp);
		break;
	}
}

static void
showtree(union node *n)
{
	trace_puts("showtree called\n");
	shtree(n, 1, NULL, stdout);
}

#define TRACE(param)    trace_printf param
#define TRACEV(param)   trace_vprintf param

#else

#define TRACE(param)
#define TRACEV(param)

#endif /* DEBUG */


/* ============ Parser data */

/*
 * ash_vmsg() needs parsefile->fd, hence parsefile definition is moved up.
 */
struct strlist {
	struct strlist *next;
	char *text;
};

#if ENABLE_ASH_ALIAS
struct alias;
#endif

struct strpush {
	struct strpush *prev;   /* preceding string on stack */
	char *prevstring;
	int prevnleft;
#if ENABLE_ASH_ALIAS
	struct alias *ap;       /* if push was associated with an alias */
#endif
	char *string;           /* remember the string since it may change */
};

struct parsefile {
	struct parsefile *prev; /* preceding file on stack */
	int linno;              /* current line */
	int fd;                 /* file descriptor (or -1 if string) */
	int nleft;              /* number of chars left in this line */
	int lleft;              /* number of chars left in this buffer */
	char *nextc;            /* next char in buffer */
	char *buf;              /* input buffer */
	struct strpush *strpush; /* for pushing strings at this level */
	struct strpush basestrpush; /* so pushing one is fast */
};

static struct parsefile basepf;         /* top level input file */
static struct parsefile *parsefile = &basepf;  /* current input file */
static int startlinno;                 /* line # where last token started */
static char *commandname;              /* currently executing command */
static struct strlist *cmdenviron;     /* environment for builtin command */
static int exitstatus;                 /* exit status of last command */


/* ============ Message printing */

static void
ash_vmsg(const char *msg, va_list ap)
{
	fprintf(stderr, "%s: ", arg0);
	if (commandname) {
		if (strcmp(arg0, commandname))
			fprintf(stderr, "%s: ", commandname);
		if (!iflag || parsefile->fd)
			fprintf(stderr, "line %d: ", startlinno);
	}
	vfprintf(stderr, msg, ap);
	outcslow('\n', stderr);
}

/*
 * Exverror is called to raise the error exception.  If the second argument
 * is not NULL then error prints an error message using printf style
 * formatting.  It then raises the error exception.
 */
static void ash_vmsg_and_raise(int, const char *, va_list) ATTRIBUTE_NORETURN;
static void
ash_vmsg_and_raise(int cond, const char *msg, va_list ap)
{
#if DEBUG
	if (msg) {
		TRACE(("ash_vmsg_and_raise(%d, \"", cond));
		TRACEV((msg, ap));
		TRACE(("\") pid=%d\n", getpid()));
	} else
		TRACE(("ash_vmsg_and_raise(%d, NULL) pid=%d\n", cond, getpid()));
	if (msg)
#endif
		ash_vmsg(msg, ap);

	flush_stdout_stderr();
	raise_exception(cond);
	/* NOTREACHED */
}

static void ash_msg_and_raise_error(const char *, ...) ATTRIBUTE_NORETURN;
static void
ash_msg_and_raise_error(const char *msg, ...)
{
	va_list ap;

	va_start(ap, msg);
	ash_vmsg_and_raise(EXERROR, msg, ap);
	/* NOTREACHED */
	va_end(ap);
}

static void ash_msg_and_raise(int, const char *, ...) ATTRIBUTE_NORETURN;
static void
ash_msg_and_raise(int cond, const char *msg, ...)
{
	va_list ap;

	va_start(ap, msg);
	ash_vmsg_and_raise(cond, msg, ap);
	/* NOTREACHED */
	va_end(ap);
}

/*
 * error/warning routines for external builtins
 */
static void
ash_msg(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	ash_vmsg(fmt, ap);
	va_end(ap);
}

/*
 * Return a string describing an error.  The returned string may be a
 * pointer to a static buffer that will be overwritten on the next call.
 * Action describes the operation that got the error.
 */
static const char *
errmsg(int e, const char *em)
{
	if (e == ENOENT || e == ENOTDIR) {
		return em;
	}
	return strerror(e);
}


/* ============ Memory allocation */

/*
 * It appears that grabstackstr() will barf with such alignments
 * because stalloc() will return a string allocated in a new stackblock.
 */
#define SHELL_ALIGN(nbytes) (((nbytes) + SHELL_SIZE) & ~SHELL_SIZE)
enum {
	/* Most machines require the value returned from malloc to be aligned
	 * in some way.  The following macro will get this right
	 * on many machines.  */
	SHELL_SIZE = sizeof(union {int i; char *cp; double d; }) - 1,
	/* Minimum size of a block */
	MINSIZE  = SHELL_ALIGN(504),
};

struct stack_block {
	struct stack_block *prev;
	char space[MINSIZE];
};

struct stackmark {
	struct stack_block *stackp;
	char *stacknxt;
	size_t stacknleft;
	struct stackmark *marknext;
};

static struct stack_block stackbase;
static struct stack_block *stackp = &stackbase;
static struct stackmark *markp;
static char *stacknxt = stackbase.space;
static size_t stacknleft = MINSIZE;
static char *sstrend = stackbase.space + MINSIZE;
static int herefd = -1;

#define stackblock() ((void *)stacknxt)
#define stackblocksize() stacknleft

static void *
ckrealloc(void * p, size_t nbytes)
{
	p = realloc(p, nbytes);
	if (!p)
		ash_msg_and_raise_error(bb_msg_memory_exhausted);
	return p;
}

static void *
ckmalloc(size_t nbytes)
{
	return ckrealloc(NULL, nbytes);
}

/*
 * Make a copy of a string in safe storage.
 */
static char *
ckstrdup(const char *s)
{
	char *p = strdup(s);
	if (!p)
		ash_msg_and_raise_error(bb_msg_memory_exhausted);
	return p;
}

/*
 * Parse trees for commands are allocated in lifo order, so we use a stack
 * to make this more efficient, and also to avoid all sorts of exception
 * handling code to handle interrupts in the middle of a parse.
 *
 * The size 504 was chosen because the Ultrix malloc handles that size
 * well.
 */
static void *
stalloc(size_t nbytes)
{
	char *p;
	size_t aligned;

	aligned = SHELL_ALIGN(nbytes);
	if (aligned > stacknleft) {
		size_t len;
		size_t blocksize;
		struct stack_block *sp;

		blocksize = aligned;
		if (blocksize < MINSIZE)
			blocksize = MINSIZE;
		len = sizeof(struct stack_block) - MINSIZE + blocksize;
		if (len < blocksize)
			ash_msg_and_raise_error(bb_msg_memory_exhausted);
		INT_OFF;
		sp = ckmalloc(len);
		sp->prev = stackp;
		stacknxt = sp->space;
		stacknleft = blocksize;
		sstrend = stacknxt + blocksize;
		stackp = sp;
		INT_ON;
	}
	p = stacknxt;
	stacknxt += aligned;
	stacknleft -= aligned;
	return p;
}

static void
stunalloc(void *p)
{
#if DEBUG
	if (!p || (stacknxt < (char *)p) || ((char *)p < stackp->space)) {
		write(2, "stunalloc\n", 10);
		abort();
	}
#endif
	stacknleft += stacknxt - (char *)p;
	stacknxt = p;
}

/*
 * Like strdup but works with the ash stack.
 */
static char *
ststrdup(const char *p)
{
	size_t len = strlen(p) + 1;
	return memcpy(stalloc(len), p, len);
}

static void
setstackmark(struct stackmark *mark)
{
	mark->stackp = stackp;
	mark->stacknxt = stacknxt;
	mark->stacknleft = stacknleft;
	mark->marknext = markp;
	markp = mark;
}

static void
popstackmark(struct stackmark *mark)
{
	struct stack_block *sp;

	INT_OFF;
	markp = mark->marknext;
	while (stackp != mark->stackp) {
		sp = stackp;
		stackp = sp->prev;
		free(sp);
	}
	stacknxt = mark->stacknxt;
	stacknleft = mark->stacknleft;
	sstrend = mark->stacknxt + mark->stacknleft;
	INT_ON;
}

/*
 * When the parser reads in a string, it wants to stick the string on the
 * stack and only adjust the stack pointer when it knows how big the
 * string is.  Stackblock (defined in stack.h) returns a pointer to a block
 * of space on top of the stack and stackblocklen returns the length of
 * this block.  Growstackblock will grow this space by at least one byte,
 * possibly moving it (like realloc).  Grabstackblock actually allocates the
 * part of the block that has been used.
 */
static void
growstackblock(void)
{
	size_t newlen;

	newlen = stacknleft * 2;
	if (newlen < stacknleft)
		ash_msg_and_raise_error(bb_msg_memory_exhausted);
	if (newlen < 128)
		newlen += 128;

	if (stacknxt == stackp->space && stackp != &stackbase) {
		struct stack_block *oldstackp;
		struct stackmark *xmark;
		struct stack_block *sp;
		struct stack_block *prevstackp;
		size_t grosslen;

		INT_OFF;
		oldstackp = stackp;
		sp = stackp;
		prevstackp = sp->prev;
		grosslen = newlen + sizeof(struct stack_block) - MINSIZE;
		sp = ckrealloc(sp, grosslen);
		sp->prev = prevstackp;
		stackp = sp;
		stacknxt = sp->space;
		stacknleft = newlen;
		sstrend = sp->space + newlen;

		/*
		 * Stack marks pointing to the start of the old block
		 * must be relocated to point to the new block
		 */
		xmark = markp;
		while (xmark != NULL && xmark->stackp == oldstackp) {
			xmark->stackp = stackp;
			xmark->stacknxt = stacknxt;
			xmark->stacknleft = stacknleft;
			xmark = xmark->marknext;
		}
		INT_ON;
	} else {
		char *oldspace = stacknxt;
		int oldlen = stacknleft;
		char *p = stalloc(newlen);

		/* free the space we just allocated */
		stacknxt = memcpy(p, oldspace, oldlen);
		stacknleft += newlen;
	}
}

static void
grabstackblock(size_t len)
{
	len = SHELL_ALIGN(len);
	stacknxt += len;
	stacknleft -= len;
}

/*
 * The following routines are somewhat easier to use than the above.
 * The user declares a variable of type STACKSTR, which may be declared
 * to be a register.  The macro STARTSTACKSTR initializes things.  Then
 * the user uses the macro STPUTC to add characters to the string.  In
 * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is
 * grown as necessary.  When the user is done, she can just leave the
 * string there and refer to it using stackblock().  Or she can allocate
 * the space for it using grabstackstr().  If it is necessary to allow
 * someone else to use the stack temporarily and then continue to grow
 * the string, the user should use grabstack to allocate the space, and
 * then call ungrabstr(p) to return to the previous mode of operation.
 *
 * USTPUTC is like STPUTC except that it doesn't check for overflow.
 * CHECKSTACKSPACE can be called before USTPUTC to ensure that there
 * is space for at least one character.
 */
static void *
growstackstr(void)
{
	size_t len = stackblocksize();
	if (herefd >= 0 && len >= 1024) {
		full_write(herefd, stackblock(), len);
		return stackblock();
	}
	growstackblock();
	return stackblock() + len;
}

/*
 * Called from CHECKSTRSPACE.
 */
static char *
makestrspace(size_t newlen, char *p)
{
	size_t len = p - stacknxt;
	size_t size = stackblocksize();

	for (;;) {
		size_t nleft;

		size = stackblocksize();
		nleft = size - len;
		if (nleft >= newlen)
			break;
		growstackblock();
	}
	return stackblock() + len;
}

static char *
stack_nputstr(const char *s, size_t n, char *p)
{
	p = makestrspace(n, p);
	p = memcpy(p, s, n) + n;
	return p;
}

static char *
stack_putstr(const char *s, char *p)
{
	return stack_nputstr(s, strlen(s), p);
}

static char *
_STPUTC(int c, char *p)
{
	if (p == sstrend)
		p = growstackstr();
	*p++ = c;
	return p;
}

#define STARTSTACKSTR(p)        ((p) = stackblock())
#define STPUTC(c, p)            ((p) = _STPUTC((c), (p)))
#define CHECKSTRSPACE(n, p) \
	do { \
		char *q = (p); \
		size_t l = (n); \
		size_t m = sstrend - q; \
		if (l > m) \
			(p) = makestrspace(l, q); \
	} while (0)
#define USTPUTC(c, p)           (*p++ = (c))
#define STACKSTRNUL(p) \
	do { \
		if ((p) == sstrend) \
			p = growstackstr(); \
		*p = '\0'; \
	} while (0)
#define STUNPUTC(p)             (--p)
#define STTOPC(p)               (p[-1])
#define STADJUST(amount, p)     (p += (amount))

#define grabstackstr(p)         stalloc((char *)(p) - (char *)stackblock())
#define ungrabstackstr(s, p)    stunalloc((s))
#define stackstrend()           ((void *)sstrend)


/* ============ String helpers */

/*
 * prefix -- see if pfx is a prefix of string.
 */
static char *
prefix(const char *string, const char *pfx)
{
	while (*pfx) {
		if (*pfx++ != *string++)
			return 0;
	}
	return (char *) string;
}

/*
 * Check for a valid number.  This should be elsewhere.
 */
static int
is_number(const char *p)
{
	do {
		if (!isdigit(*p))
			return 0;
	} while (*++p != '\0');
	return 1;
}

/*
 * Convert a string of digits to an integer, printing an error message on
 * failure.
 */
static int
number(const char *s)
{
	if (!is_number(s))
		ash_msg_and_raise_error(illnum, s);
	return atoi(s);
}

/*
 * Produce a possibly single quoted string suitable as input to the shell.
 * The return string is allocated on the stack.
 */
static char *
single_quote(const char *s)
{
	char *p;

	STARTSTACKSTR(p);

	do {
		char *q;
		size_t len;

		len = strchrnul(s, '\'') - s;

		q = p = makestrspace(len + 3, p);

		*q++ = '\'';
		q = memcpy(q, s, len) + len;
		*q++ = '\'';
		s += len;

		STADJUST(q - p, p);

		len = strspn(s, "'");
		if (!len)
			break;

		q = p = makestrspace(len + 3, p);

		*q++ = '"';
		q = memcpy(q, s, len) + len;
		*q++ = '"';
		s += len;

		STADJUST(q - p, p);
	} while (*s);

	USTPUTC(0, p);

	return stackblock();
}


/* ============ nextopt */

static char **argptr;                  /* argument list for builtin commands */
static char *optionarg;                /* set by nextopt (like getopt) */
static char *optptr;                   /* used by nextopt */

/*
 * XXX - should get rid of.  have all builtins use getopt(3).  the
 * library getopt must have the BSD extension static variable "optreset"
 * otherwise it can't be used within the shell safely.
 *
 * Standard option processing (a la getopt) for builtin routines.  The
 * only argument that is passed to nextopt is the option string; the
 * other arguments are unnecessary.  It return the character, or '\0' on
 * end of input.
 */
static int
nextopt(const char *optstring)
{
	char *p;
	const char *q;
	char c;

	p = optptr;
	if (p == NULL || *p == '\0') {
		p = *argptr;
		if (p == NULL || *p != '-' || *++p == '\0')
			return '\0';
		argptr++;
		if (LONE_DASH(p))        /* check for "--" */
			return '\0';
	}
	c = *p++;
	for (q = optstring; *q != c; ) {
		if (*q == '\0')
			ash_msg_and_raise_error("illegal option -%c", c);
		if (*++q == ':')
			q++;
	}
	if (*++q == ':') {
		if (*p == '\0' && (p = *argptr++) == NULL)
			ash_msg_and_raise_error("no arg for -%c option", c);
		optionarg = p;
		p = NULL;
	}
	optptr = p;
	return c;
}


/* ============ Math support definitions */

#if ENABLE_ASH_MATH_SUPPORT_64
typedef int64_t arith_t;
#define arith_t_type long long
#else
typedef long arith_t;
#define arith_t_type long
#endif

#if ENABLE_ASH_MATH_SUPPORT
static arith_t dash_arith(const char *);
static arith_t arith(const char *expr, int *perrcode);
#endif

#if ENABLE_ASH_RANDOM_SUPPORT
static unsigned long rseed;
#ifndef DYNAMIC_VAR
#define DYNAMIC_VAR
#endif
#endif


/* ============ Shell variables */

/* flags */
#define VEXPORT         0x01    /* variable is exported */
#define VREADONLY       0x02    /* variable cannot be modified */
#define VSTRFIXED       0x04    /* variable struct is statically allocated */
#define VTEXTFIXED      0x08    /* text is statically allocated */
#define VSTACK          0x10    /* text is allocated on the stack */
#define VUNSET          0x20    /* the variable is not set */
#define VNOFUNC         0x40    /* don't call the callback function */
#define VNOSET          0x80    /* do not set variable - just readonly test */
#define VNOSAVE         0x100   /* when text is on the heap before setvareq */
#ifdef DYNAMIC_VAR
# define VDYNAMIC       0x200   /* dynamic variable */
#else
# define VDYNAMIC       0
#endif

static const char defpathvar[] = "PATH=/usr/local/bin:/usr/bin:/sbin:/bin";
#ifdef IFS_BROKEN
static const char defifsvar[] = "IFS= \t\n";
#define defifs (defifsvar + 4)
#else
static const char defifs[] = " \t\n";
#endif

struct shparam {
	int nparam;             /* # of positional parameters (without $0) */
	unsigned char malloc;   /* if parameter list dynamically allocated */
	char **p;               /* parameter list */
#if ENABLE_ASH_GETOPTS
	int optind;             /* next parameter to be processed by getopts */
	int optoff;             /* used by getopts */
#endif
};

static struct shparam shellparam;      /* $@ current positional parameters */

/*
 * Free the list of positional parameters.
 */
static void
freeparam(volatile struct shparam *param)
{
	char **ap;

	if (param->malloc) {
		for (ap = param->p; *ap; ap++)
			free(*ap);
		free(param->p);
	}
}

#if ENABLE_ASH_GETOPTS
static void
getoptsreset(const char *value)
{
	shellparam.optind = number(value);
	shellparam.optoff = -1;
}
#endif

struct var {
	struct var *next;               /* next entry in hash list */
	int flags;                      /* flags are defined above */
	const char *text;               /* name=value */
	void (*func)(const char *);     /* function to be called when  */
					/* the variable gets set/unset */
};

struct localvar {
	struct localvar *next;          /* next local variable in list */
	struct var *vp;                 /* the variable that was made local */
	int flags;                      /* saved flags */
	const char *text;               /* saved text */
};

/* Forward decls for varinit[] */
#if ENABLE_LOCALE_SUPPORT
static void
change_lc_all(const char *value)
{
	if (value && *value != '\0')
		setlocale(LC_ALL, value);
}
static void
change_lc_ctype(const char *value)
{
	if (value && *value != '\0')
		setlocale(LC_CTYPE, value);
}
#endif
#if ENABLE_ASH_MAIL
static void chkmail(void);
static void changemail(const char *);
#endif
static void changepath(const char *);
#if ENABLE_ASH_RANDOM_SUPPORT
static void change_random(const char *);
#endif

static struct var varinit[] = {
#ifdef IFS_BROKEN
	{ NULL, VSTRFIXED|VTEXTFIXED,           defifsvar,      NULL },
#else
	{ NULL, VSTRFIXED|VTEXTFIXED|VUNSET,    "IFS\0",        NULL },
#endif
#if ENABLE_ASH_MAIL
	{ NULL, VSTRFIXED|VTEXTFIXED|VUNSET,    "MAIL\0",       changemail },
	{ NULL, VSTRFIXED|VTEXTFIXED|VUNSET,    "MAILPATH\0",   changemail },
#endif
	{ NULL, VSTRFIXED|VTEXTFIXED,           defpathvar,     changepath },
	{ NULL, VSTRFIXED|VTEXTFIXED,           "PS1=$ ",       NULL },
	{ NULL, VSTRFIXED|VTEXTFIXED,           "PS2=> ",       NULL },
	{ NULL, VSTRFIXED|VTEXTFIXED,           "PS4=+ ",       NULL },
#if ENABLE_ASH_GETOPTS
	{ NULL, VSTRFIXED|VTEXTFIXED,           "OPTIND=1",     getoptsreset },
#endif
#if ENABLE_ASH_RANDOM_SUPPORT
	{ NULL, VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "RANDOM\0", change_random },
#endif
#if ENABLE_LOCALE_SUPPORT
	{ NULL, VSTRFIXED | VTEXTFIXED | VUNSET, "LC_ALL\0",    change_lc_all },
	{ NULL, VSTRFIXED | VTEXTFIXED | VUNSET, "LC_CTYPE\0",  change_lc_ctype },
#endif
#if ENABLE_FEATURE_EDITING_SAVEHISTORY
	{ NULL, VSTRFIXED | VTEXTFIXED | VUNSET, "HISTFILE\0",  NULL },
#endif
};

#define vifs varinit[0]
#if ENABLE_ASH_MAIL
#define vmail (&vifs)[1]
#define vmpath (&vmail)[1]
#else
#define vmpath vifs
#endif
#define vpath (&vmpath)[1]
#define vps1 (&vpath)[1]
#define vps2 (&vps1)[1]
#define vps4 (&vps2)[1]
#define voptind (&vps4)[1]
#if ENABLE_ASH_GETOPTS
#define vrandom (&voptind)[1]
#else
#define vrandom (&vps4)[1]
#endif
#define defpath (defpathvar + 5)

/*
 * The following macros access the values of the above variables.
 * They have to skip over the name.  They return the null string
 * for unset variables.
 */
#define ifsval()        (vifs.text + 4)
#define ifsset()        ((vifs.flags & VUNSET) == 0)
#define mailval()       (vmail.text + 5)
#define mpathval()      (vmpath.text + 9)
#define pathval()       (vpath.text + 5)
#define ps1val()        (vps1.text + 4)
#define ps2val()        (vps2.text + 4)
#define ps4val()        (vps4.text + 4)
#define optindval()     (voptind.text + 7)

#define mpathset()      ((vmpath.flags & VUNSET) == 0)

/*
 * The parsefile structure pointed to by the global variable parsefile
 * contains information about the current file being read.
 */
struct redirtab {
	struct redirtab *next;
	int renamed[10];
	int nullredirs;
};

static struct redirtab *redirlist;
static int nullredirs;
extern char **environ;
static int preverrout_fd;   /* save fd2 before print debug if xflag is set. */

#define VTABSIZE 39

static struct var *vartab[VTABSIZE];

#define is_name(c)      ((c) == '_' || isalpha((unsigned char)(c)))
#define is_in_name(c)   ((c) == '_' || isalnum((unsigned char)(c)))

/*
 * Return of a legal variable name (a letter or underscore followed by zero or
 * more letters, underscores, and digits).
 */
static char *
endofname(const char *name)
{
	char *p;

	p = (char *) name;
	if (!is_name(*p))
		return p;
	while (*++p) {
		if (!is_in_name(*p))
			break;
	}
	return p;
}

/*
 * Compares two strings up to the first = or '\0'.  The first
 * string must be terminated by '='; the second may be terminated by
 * either '=' or '\0'.
 */
static int
varcmp(const char *p, const char *q)
{
	int c, d;

	while ((c = *p) == (d = *q)) {
		if (!c || c == '=')
			goto out;
		p++;
		q++;
	}
	if (c == '=')
		c = '\0';
	if (d == '=')
		d = '\0';
 out:
	return c - d;
}

static int
varequal(const char *a, const char *b)
{
	return !varcmp(a, b);
}

/*
 * Find the appropriate entry in the hash table from the name.
 */
static struct var **
hashvar(const char *p)
{
	unsigned hashval;

	hashval = ((unsigned char) *p) << 4;
	while (*p && *p != '=')
		hashval += (unsigned char) *p++;
	return &vartab[hashval % VTABSIZE];
}

static int
vpcmp(const void *a, const void *b)
{
	return varcmp(*(const char **)a, *(const char **)b);
}

/*
 * This routine initializes the builtin variables.
 */
static void
initvar(void)
{
	struct var *vp;
	struct var *end;
	struct var **vpp;

	/*
	 * PS1 depends on uid
	 */
#if ENABLE_FEATURE_EDITING && ENABLE_FEATURE_EDITING_FANCY_PROMPT
	vps1.text = "PS1=\\w \\$ ";
#else
	if (!geteuid())
		vps1.text = "PS1=# ";
#endif
	vp = varinit;
	end = vp + sizeof(varinit) / sizeof(varinit[0]);
	do {
		vpp = hashvar(vp->text);
		vp->next = *vpp;
		*vpp = vp;
	} while (++vp < end);
}

static struct var **
findvar(struct var **vpp, const char *name)
{
	for (; *vpp; vpp = &(*vpp)->next) {
		if (varequal((*vpp)->text, name)) {
			break;
		}
	}
	return vpp;
}

/*
 * Find the value of a variable.  Returns NULL if not set.
 */
static char *
lookupvar(const char *name)
{
	struct var *v;

	v = *findvar(hashvar(name), name);
	if (v) {
#ifdef DYNAMIC_VAR
	/*
	 * Dynamic variables are implemented roughly the same way they are
	 * in bash. Namely, they're "special" so long as they aren't unset.
	 * As soon as they're unset, they're no longer dynamic, and dynamic
	 * lookup will no longer happen at that point. -- PFM.
	 */
		if ((v->flags & VDYNAMIC))
			(*v->func)(NULL);
#endif
		if (!(v->flags & VUNSET))
			return strchrnul(v->text, '=') + 1;
	}
	return NULL;
}

/*
 * Search the environment of a builtin command.
 */
static char *
bltinlookup(const char *name)
{
	struct strlist *sp;

	for (sp = cmdenviron; sp; sp = sp->next) {
		if (varequal(sp->text, name))
			return strchrnul(sp->text, '=') + 1;
	}
	return lookupvar(name);
}

/*
 * Same as setvar except that the variable and value are passed in
 * the first argument as name=value.  Since the first argument will
 * be actually stored in the table, it should not be a string that
 * will go away.
 * Called with interrupts off.
 */
static void
setvareq(char *s, int flags)
{
	struct var *vp, **vpp;

	vpp = hashvar(s);
	flags |= (VEXPORT & (((unsigned) (1 - aflag)) - 1));
	vp = *findvar(vpp, s);
	if (vp) {
		if ((vp->flags & (VREADONLY|VDYNAMIC)) == VREADONLY) {
			const char *n;

			if (flags & VNOSAVE)
				free(s);
			n = vp->text;
			ash_msg_and_raise_error("%.*s: is read only", strchrnul(n, '=') - n, n);
		}

		if (flags & VNOSET)
			return;

		if (vp->func && (flags & VNOFUNC) == 0)
			(*vp->func)(strchrnul(s, '=') + 1);

		if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
			free((char*)vp->text);

		flags |= vp->flags & ~(VTEXTFIXED|VSTACK|VNOSAVE|VUNSET);
	} else {
		if (flags & VNOSET)
			return;
		/* not found */
		vp = ckmalloc(sizeof(*vp));
		vp->next = *vpp;
		vp->func = NULL;
		*vpp = vp;
	}
	if (!(flags & (VTEXTFIXED|VSTACK|VNOSAVE)))
		s = ckstrdup(s);
	vp->text = s;
	vp->flags = flags;
}

/*
 * Set the value of a variable.  The flags argument is ored with the
 * flags of the variable.  If val is NULL, the variable is unset.
 */
static void
setvar(const char *name, const char *val, int flags)
{
	char *p, *q;
	size_t namelen;
	char *nameeq;
	size_t vallen;

	q = endofname(name);
	p = strchrnul(q, '=');
	namelen = p - name;
	if (!namelen || p != q)
		ash_msg_and_raise_error("%.*s: bad variable name", namelen, name);
	vallen = 0;
	if (val == NULL) {
		flags |= VUNSET;
	} else {
		vallen = strlen(val);
	}
	INT_OFF;
	nameeq = ckmalloc(namelen + vallen + 2);
	p = memcpy(nameeq, name, namelen) + namelen;
	if (val) {
		*p++ = '=';
		p = memcpy(p, val, vallen) + vallen;
	}
	*p = '\0';
	setvareq(nameeq, flags | VNOSAVE);
	INT_ON;
}

#if ENABLE_ASH_GETOPTS
/*
 * Safe version of setvar, returns 1 on success 0 on failure.
 */
static int
setvarsafe(const char *name, const char *val, int flags)
{
	int err;
	volatile int saveint;
	struct jmploc *volatile savehandler = exception_handler;
	struct jmploc jmploc;

	SAVE_INT(saveint);
	if (setjmp(jmploc.loc))
		err = 1;
	else {
		exception_handler = &jmploc;
		setvar(name, val, flags);
		err = 0;
	}
	exception_handler = savehandler;
	RESTORE_INT(saveint);
	return err;
}
#endif

/*
 * Unset the specified variable.
 */
static int
unsetvar(const char *s)
{
	struct var **vpp;
	struct var *vp;
	int retval;

	vpp = findvar(hashvar(s), s);
	vp = *vpp;
	retval = 2;
	if (vp) {
		int flags = vp->flags;

		retval = 1;
		if (flags & VREADONLY)
			goto out;
#ifdef DYNAMIC_VAR
		vp->flags &= ~VDYNAMIC;
#endif
		if (flags & VUNSET)
			goto ok;
		if ((flags & VSTRFIXED) == 0) {
			INT_OFF;
			if ((flags & (VTEXTFIXED|VSTACK)) == 0)
				free((char*)vp->text);
			*vpp = vp->next;
			free(vp);
			INT_ON;
		} else {
			setvar(s, 0, 0);
			vp->flags &= ~VEXPORT;
		}
 ok:
		retval = 0;
	}
 out:
	return retval;
}

/*
 * Process a linked list of variable assignments.
 */
static void
listsetvar(struct strlist *list_set_var, int flags)
{
	struct strlist *lp = list_set_var;

	if (!lp)
		return;
	INT_OFF;
	do {
		setvareq(lp->text, flags);
		lp = lp->next;
	} while (lp);
	INT_ON;
}

/*
 * Generate a list of variables satisfying the given conditions.
 */
static char **
listvars(int on, int off, char ***end)
{
	struct var **vpp;
	struct var *vp;
	char **ep;
	int mask;

	STARTSTACKSTR(ep);
	vpp = vartab;
	mask = on | off;
	do {
		for (vp = *vpp; vp; vp = vp->next) {
			if ((vp->flags & mask) == on) {
				if (ep == stackstrend())
					ep = growstackstr();
				*ep++ = (char *) vp->text;
			}
		}
	} while (++vpp < vartab + VTABSIZE);
	if (ep == stackstrend())
		ep = growstackstr();
	if (end)
		*end = ep;
	*ep++ = NULL;
	return grabstackstr(ep);
}


/* ============ Path search helper
 *
 * The variable path (passed by reference) should be set to the start
 * of the path before the first call; padvance will update
 * this value as it proceeds.  Successive calls to padvance will return
 * the possible path expansions in sequence.  If an option (indicated by
 * a percent sign) appears in the path entry then the global variable
 * pathopt will be set to point to it; otherwise pathopt will be set to
 * NULL.
 */
static const char *pathopt;     /* set by padvance */

static char *
padvance(const char **path, const char *name)
{
	const char *p;
	char *q;
	const char *start;
	size_t len;

	if (*path == NULL)
		return NULL;
	start = *path;
	for (p = start; *p && *p != ':' && *p != '%'; p++);
	len = p - start + strlen(name) + 2;     /* "2" is for '/' and '\0' */
	while (stackblocksize() < len)
		growstackblock();
	q = stackblock();
	if (p != start) {
		memcpy(q, start, p - start);
		q += p - start;
		*q++ = '/';
	}
	strcpy(q, name);
	pathopt = NULL;
	if (*p == '%') {
		pathopt = ++p;
		while (*p && *p != ':') p++;
	}
	if (*p == ':')
		*path = p + 1;
	else
		*path = NULL;
	return stalloc(len);
}


/* ============ Prompt */

static int doprompt;                   /* if set, prompt the user */
static int needprompt;                 /* true if interactive and at start of line */

#if ENABLE_FEATURE_EDITING
static line_input_t *line_input_state;
static const char *cmdedit_prompt;
static void
putprompt(const char *s)
{
	if (ENABLE_ASH_EXPAND_PRMT) {
		free((char*)cmdedit_prompt);
		cmdedit_prompt = ckstrdup(s);
		return;
	}
	cmdedit_prompt = s;
}
#else
static void
putprompt(const char *s)
{
	out2str(s);
}
#endif

#if ENABLE_ASH_EXPAND_PRMT
/* expandstr() needs parsing machinery, so it is far away ahead... */
static const char *expandstr(const char *ps);
#else
#define expandstr(s) s
#endif

static void
setprompt(int whichprompt)
{
	const char *prompt;
#if ENABLE_ASH_EXPAND_PRMT
	struct stackmark smark;
#endif

	needprompt = 0;

	switch (whichprompt) {
	case 1:
		prompt = ps1val();
		break;
	case 2:
		prompt = ps2val();
		break;
	default:                        /* 0 */
		prompt = nullstr;
	}
#if ENABLE_ASH_EXPAND_PRMT
	setstackmark(&smark);
	stalloc(stackblocksize());
#endif
	putprompt(expandstr(prompt));
#if ENABLE_ASH_EXPAND_PRMT
	popstackmark(&smark);
#endif
}


/* ============ The cd and pwd commands */

#define CD_PHYSICAL 1
#define CD_PRINT 2

static int docd(const char *, int);

static char *curdir = nullstr;          /* current working directory */
static char *physdir = nullstr;         /* physical working directory */

static int
cdopt(void)
{
	int flags = 0;
	int i, j;

	j = 'L';
	while ((i = nextopt("LP"))) {
		if (i != j) {
			flags ^= CD_PHYSICAL;
			j = i;
		}
	}

	return flags;
}

/*
 * Update curdir (the name of the current directory) in response to a
 * cd command.
 */
static const char *
updatepwd(const char *dir)
{
	char *new;
	char *p;
	char *cdcomppath;
	const char *lim;

	cdcomppath = ststrdup(dir);
	STARTSTACKSTR(new);
	if (*dir != '/') {
		if (curdir == nullstr)
			return 0;
		new = stack_putstr(curdir, new);
	}
	new = makestrspace(strlen(dir) + 2, new);
	lim = stackblock() + 1;
	if (*dir != '/') {
		if (new[-1] != '/')
			USTPUTC('/', new);
		if (new > lim && *lim == '/')
			lim++;
	} else {
		USTPUTC('/', new);
		cdcomppath++;
		if (dir[1] == '/' && dir[2] != '/') {
			USTPUTC('/', new);
			cdcomppath++;
			lim++;
		}
	}
	p = strtok(cdcomppath, "/");
	while (p) {
		switch (*p) {
		case '.':
			if (p[1] == '.' && p[2] == '\0') {
				while (new > lim) {
					STUNPUTC(new);
					if (new[-1] == '/')
						break;
				}
				break;
			} else if (p[1] == '\0')
				break;
			/* fall through */
		default:
			new = stack_putstr(p, new);
			USTPUTC('/', new);
		}
		p = strtok(0, "/");
	}
	if (new > lim)
		STUNPUTC(new);
	*new = 0;
	return stackblock();
}

/*
 * Find out what the current directory is. If we already know the current
 * directory, this routine returns immediately.
 */
static char *
getpwd(void)
{
	char *dir = getcwd(0, 0);
	return dir ? dir : nullstr;
}

static void
setpwd(const char *val, int setold)
{
	char *oldcur, *dir;

	oldcur = dir = curdir;

	if (setold) {
		setvar("OLDPWD", oldcur, VEXPORT);
	}
	INT_OFF;
	if (physdir != nullstr) {
		if (physdir != oldcur)
			free(physdir);
		physdir = nullstr;
	}
	if (oldcur == val || !val) {
		char *s = getpwd();
		physdir = s;
		if (!val)
			dir = s;
	} else
		dir = ckstrdup(val);
	if (oldcur != dir && oldcur != nullstr) {
		free(oldcur);
	}
	curdir = dir;
	INT_ON;
	setvar("PWD", dir, VEXPORT);
}

static void hashcd(void);

/*
 * Actually do the chdir.  We also call hashcd to let the routines in exec.c
 * know that the current directory has changed.
 */
static int
docd(const char *dest, int flags)
{
	const char *dir = 0;
	int err;

	TRACE(("docd(\"%s\", %d) called\n", dest, flags));

	INT_OFF;
	if (!(flags & CD_PHYSICAL)) {
		dir = updatepwd(dest);
		if (dir)
			dest = dir;
	}
	err = chdir(dest);
	if (err)
		goto out;
	setpwd(dir, 1);
	hashcd();
 out:
	INT_ON;
	return err;
}

static int
cdcmd(int argc, char **argv)
{
	const char *dest;
	const char *path;
	const char *p;
	char c;
	struct stat statb;
	int flags;

	flags = cdopt();
	dest = *argptr;
	if (!dest)
		dest = bltinlookup(homestr);
	else if (LONE_DASH(dest)) {
		dest = bltinlookup("OLDPWD");
		flags |= CD_PRINT;
	}
	if (!dest)
		dest = nullstr;
	if (*dest == '/')
		goto step7;
	if (*dest == '.') {
		c = dest[1];
 dotdot:
		switch (c) {
		case '\0':
		case '/':
			goto step6;
		case '.':
			c = dest[2];
			if (c != '.')
				goto dotdot;
		}
	}
	if (!*dest)
		dest = ".";
	path = bltinlookup("CDPATH");
	if (!path) {
 step6:
 step7:
		p = dest;
		goto docd;
	}
	do {
		c = *path;
		p = padvance(&path, dest);
		if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) {
			if (c && c != ':')
				flags |= CD_PRINT;
 docd:
			if (!docd(p, flags))
				goto out;
			break;
		}
	} while (path);
	ash_msg_and_raise_error("can't cd to %s", dest);
	/* NOTREACHED */
 out:
	if (flags & CD_PRINT)
		out1fmt(snlfmt, curdir);
	return 0;
}

static int
pwdcmd(int argc, char **argv)
{
	int flags;
	const char *dir = curdir;

	flags = cdopt();
	if (flags) {
		if (physdir == nullstr)
			setpwd(dir, 0);
		dir = physdir;
	}
	out1fmt(snlfmt, dir);
	return 0;
}


/* ============ ... */

#define IBUFSIZ (BUFSIZ + 1)
#define basebuf bb_common_bufsiz1       /* buffer for top level input file */

/* Syntax classes */
#define CWORD 0                 /* character is nothing special */
#define CNL 1                   /* newline character */
#define CBACK 2                 /* a backslash character */
#define CSQUOTE 3               /* single quote */
#define CDQUOTE 4               /* double quote */
#define CENDQUOTE 5             /* a terminating quote */
#define CBQUOTE 6               /* backwards single quote */
#define CVAR 7                  /* a dollar sign */
#define CENDVAR 8               /* a '}' character */
#define CLP 9                   /* a left paren in arithmetic */
#define CRP 10                  /* a right paren in arithmetic */
#define CENDFILE 11             /* end of file */
#define CCTL 12                 /* like CWORD, except it must be escaped */
#define CSPCL 13                /* these terminate a word */
#define CIGN 14                 /* character should be ignored */

#if ENABLE_ASH_ALIAS
#define SYNBASE 130
#define PEOF -130
#define PEOA -129
#define PEOA_OR_PEOF PEOA
#else
#define SYNBASE 129
#define PEOF -129
#define PEOA_OR_PEOF PEOF
#endif

/* number syntax index */
#define BASESYNTAX 0    /* not in quotes */
#define DQSYNTAX   1    /* in double quotes */
#define SQSYNTAX   2    /* in single quotes */
#define ARISYNTAX  3    /* in arithmetic */

#if ENABLE_ASH_OPTIMIZE_FOR_SIZE
#define USE_SIT_FUNCTION
#endif

#if ENABLE_ASH_MATH_SUPPORT
static const char S_I_T[][4] = {
#if ENABLE_ASH_ALIAS
	{ CSPCL, CIGN, CIGN, CIGN },            /* 0, PEOA */
#endif
	{ CSPCL, CWORD, CWORD, CWORD },         /* 1, ' ' */
	{ CNL, CNL, CNL, CNL },                 /* 2, \n */
	{ CWORD, CCTL, CCTL, CWORD },           /* 3, !*-/:=?[]~ */
	{ CDQUOTE, CENDQUOTE, CWORD, CWORD },   /* 4, '"' */
	{ CVAR, CVAR, CWORD, CVAR },            /* 5, $ */
	{ CSQUOTE, CWORD, CENDQUOTE, CWORD },   /* 6, "'" */
	{ CSPCL, CWORD, CWORD, CLP },           /* 7, ( */
	{ CSPCL, CWORD, CWORD, CRP },           /* 8, ) */
	{ CBACK, CBACK, CCTL, CBACK },          /* 9, \ */
	{ CBQUOTE, CBQUOTE, CWORD, CBQUOTE },   /* 10, ` */
	{ CENDVAR, CENDVAR, CWORD, CENDVAR },   /* 11, } */
#ifndef USE_SIT_FUNCTION
	{ CENDFILE, CENDFILE, CENDFILE, CENDFILE }, /* 12, PEOF */
	{ CWORD, CWORD, CWORD, CWORD },         /* 13, 0-9A-Za-z */
	{ CCTL, CCTL, CCTL, CCTL }              /* 14, CTLESC ... */
#endif
};
#else
static const char S_I_T[][3] = {
#if ENABLE_ASH_ALIAS
	{ CSPCL, CIGN, CIGN },                  /* 0, PEOA */
#endif
	{ CSPCL, CWORD, CWORD },                /* 1, ' ' */
	{ CNL, CNL, CNL },                      /* 2, \n */
	{ CWORD, CCTL, CCTL },                  /* 3, !*-/:=?[]~ */
	{ CDQUOTE, CENDQUOTE, CWORD },          /* 4, '"' */
	{ CVAR, CVAR, CWORD },                  /* 5, $ */
	{ CSQUOTE, CWORD, CENDQUOTE },          /* 6, "'" */
	{ CSPCL, CWORD, CWORD },                /* 7, ( */
	{ CSPCL, CWORD, CWORD },                /* 8, ) */
	{ CBACK, CBACK, CCTL },                 /* 9, \ */
	{ CBQUOTE, CBQUOTE, CWORD },            /* 10, ` */
	{ CENDVAR, CENDVAR, CWORD },            /* 11, } */
#ifndef USE_SIT_FUNCTION
	{ CENDFILE, CENDFILE, CENDFILE },       /* 12, PEOF */
	{ CWORD, CWORD, CWORD },                /* 13, 0-9A-Za-z */
	{ CCTL, CCTL, CCTL }                    /* 14, CTLESC ... */
#endif
};
#endif /* ASH_MATH_SUPPORT */

#ifdef USE_SIT_FUNCTION

static int
SIT(int c, int syntax)
{
	static const char spec_symbls[] = "\t\n !\"$&'()*-/:;<=>?[\\]`|}~";
#if ENABLE_ASH_ALIAS
	static const char syntax_index_table[] = {
		1, 2, 1, 3, 4, 5, 1, 6,         /* "\t\n !\"$&'" */
		7, 8, 3, 3, 3, 3, 1, 1,         /* "()*-/:;<" */
		3, 1, 3, 3, 9, 3, 10, 1,        /* "=>?[\\]`|" */
		11, 3                           /* "}~" */
	};
#else
	static const char syntax_index_table[] = {
		0, 1, 0, 2, 3, 4, 0, 5,         /* "\t\n !\"$&'" */
		6, 7, 2, 2, 2, 2, 0, 0,         /* "()*-/:;<" */
		2, 0, 2, 2, 8, 2, 9, 0,         /* "=>?[\\]`|" */
		10, 2                           /* "}~" */
	};
#endif
	const char *s;
	int indx;

	if (c == PEOF)          /* 2^8+2 */
		return CENDFILE;
#if ENABLE_ASH_ALIAS
	if (c == PEOA)          /* 2^8+1 */
		indx = 0;
	else
#endif
#define U_C(c) ((unsigned char)(c))

	if ((unsigned char)c >= (unsigned char)(CTLESC)
	 && (unsigned char)c <= (unsigned char)(CTLQUOTEMARK)
	) {
		return CCTL;
	} else {
		s = strchr(spec_symbls, c);
		if (s == NULL || *s == '\0')
			return CWORD;
		indx = syntax_index_table[(s - spec_symbls)];
	}
	return S_I_T[indx][syntax];
}

#else   /* !USE_SIT_FUNCTION */

#if ENABLE_ASH_ALIAS
#define CSPCL_CIGN_CIGN_CIGN                     0
#define CSPCL_CWORD_CWORD_CWORD                  1
#define CNL_CNL_CNL_CNL                          2
#define CWORD_CCTL_CCTL_CWORD                    3
#define CDQUOTE_CENDQUOTE_CWORD_CWORD            4
#define CVAR_CVAR_CWORD_CVAR                     5
#define CSQUOTE_CWORD_CENDQUOTE_CWORD            6
#define CSPCL_CWORD_CWORD_CLP                    7
#define CSPCL_CWORD_CWORD_CRP                    8
#define CBACK_CBACK_CCTL_CBACK                   9
#define CBQUOTE_CBQUOTE_CWORD_CBQUOTE           10
#define CENDVAR_CENDVAR_CWORD_CENDVAR           11
#define CENDFILE_CENDFILE_CENDFILE_CENDFILE     12
#define CWORD_CWORD_CWORD_CWORD                 13
#define CCTL_CCTL_CCTL_CCTL                     14
#else
#define CSPCL_CWORD_CWORD_CWORD                  0
#define CNL_CNL_CNL_CNL                          1
#define CWORD_CCTL_CCTL_CWORD                    2
#define CDQUOTE_CENDQUOTE_CWORD_CWORD            3
#define CVAR_CVAR_CWORD_CVAR                     4
#define CSQUOTE_CWORD_CENDQUOTE_CWORD            5
#define CSPCL_CWORD_CWORD_CLP                    6
#define CSPCL_CWORD_CWORD_CRP                    7
#define CBACK_CBACK_CCTL_CBACK                   8
#define CBQUOTE_CBQUOTE_CWORD_CBQUOTE            9
#define CENDVAR_CENDVAR_CWORD_CENDVAR           10
#define CENDFILE_CENDFILE_CENDFILE_CENDFILE     11
#define CWORD_CWORD_CWORD_CWORD                 12
#define CCTL_CCTL_CCTL_CCTL                     13
#endif

static const char syntax_index_table[258] = {
	/* BASESYNTAX_DQSYNTAX_SQSYNTAX_ARISYNTAX */
	/*   0  PEOF */      CENDFILE_CENDFILE_CENDFILE_CENDFILE,
#if ENABLE_ASH_ALIAS
	/*   1  PEOA */      CSPCL_CIGN_CIGN_CIGN,
#endif
	/*   2  -128 0x80 */ CWORD_CWORD_CWORD_CWORD,
	/*   3  -127 CTLESC       */ CCTL_CCTL_CCTL_CCTL,
	/*   4  -126 CTLVAR       */ CCTL_CCTL_CCTL_CCTL,
	/*   5  -125 CTLENDVAR    */ CCTL_CCTL_CCTL_CCTL,
	/*   6  -124 CTLBACKQ     */ CCTL_CCTL_CCTL_CCTL,
	/*   7  -123 CTLQUOTE     */ CCTL_CCTL_CCTL_CCTL,
	/*   8  -122 CTLARI       */ CCTL_CCTL_CCTL_CCTL,
	/*   9  -121 CTLENDARI    */ CCTL_CCTL_CCTL_CCTL,
	/*  10  -120 CTLQUOTEMARK */ CCTL_CCTL_CCTL_CCTL,
	/*  11  -119      */ CWORD_CWORD_CWORD_CWORD,
	/*  12  -118      */ CWORD_CWORD_CWORD_CWORD,
	/*  13  -117      */ CWORD_CWORD_CWORD_CWORD,
	/*  14  -116      */ CWORD_CWORD_CWORD_CWORD,
	/*  15  -115      */ CWORD_CWORD_CWORD_CWORD,
	/*  16  -114      */ CWORD_CWORD_CWORD_CWORD,
	/*  17  -113      */ CWORD_CWORD_CWORD_CWORD,
	/*  18  -112      */ CWORD_CWORD_CWORD_CWORD,
	/*  19  -111      */ CWORD_CWORD_CWORD_CWORD,
	/*  20  -110      */ CWORD_CWORD_CWORD_CWORD,
	/*  21  -109      */ CWORD_CWORD_CWORD_CWORD,
	/*  22  -108      */ CWORD_CWORD_CWORD_CWORD,
	/*  23  -107      */ CWORD_CWORD_CWORD_CWORD,
	/*  24  -106      */ CWORD_CWORD_CWORD_CWORD,
	/*  25  -105      */ CWORD_CWORD_CWORD_CWORD,
	/*  26  -104      */ CWORD_CWORD_CWORD_CWORD,
	/*  27  -103      */ CWORD_CWORD_CWORD_CWORD,
	/*  28  -102      */ CWORD_CWORD_CWORD_CWORD,
	/*  29  -101      */ CWORD_CWORD_CWORD_CWORD,
	/*  30  -100      */ CWORD_CWORD_CWORD_CWORD,
	/*  31   -99      */ CWORD_CWORD_CWORD_CWORD,
	/*  32   -98      */ CWORD_CWORD_CWORD_CWORD,
	/*  33   -97      */ CWORD_CWORD_CWORD_CWORD,
	/*  34   -96      */ CWORD_CWORD_CWORD_CWORD,
	/*  35   -95      */ CWORD_CWORD_CWORD_CWORD,
	/*  36   -94      */ CWORD_CWORD_CWORD_CWORD,
	/*  37   -93      */ CWORD_CWORD_CWORD_CWORD,
	/*  38   -92      */ CWORD_CWORD_CWORD_CWORD,
	/*  39   -91      */ CWORD_CWORD_CWORD_CWORD,
	/*  40   -90      */ CWORD_CWORD_CWORD_CWORD,
	/*  41   -89      */ CWORD_CWORD_CWORD_CWORD,
	/*  42   -88      */ CWORD_CWORD_CWORD_CWORD,
	/*  43   -87      */ CWORD_CWORD_CWORD_CWORD,
	/*  44   -86      */ CWORD_CWORD_CWORD_CWORD,
	/*  45   -85      */ CWORD_CWORD_CWORD_CWORD,
	/*  46   -84      */ CWORD_CWORD_CWORD_CWORD,
	/*  47   -83      */ CWORD_CWORD_CWORD_CWORD,
	/*  48   -82      */ CWORD_CWORD_CWORD_CWORD,
	/*  49   -81      */ CWORD_CWORD_CWORD_CWORD,
	/*  50   -80      */ CWORD_CWORD_CWORD_CWORD,
	/*  51   -79      */ CWORD_CWORD_CWORD_CWORD,
	/*  52   -78      */ CWORD_CWORD_CWORD_CWORD,
	/*  53   -77      */ CWORD_CWORD_CWORD_CWORD,
	/*  54   -76      */ CWORD_CWORD_CWORD_CWORD,
	/*  55   -75      */ CWORD_CWORD_CWORD_CWORD,
	/*  56   -74      */ CWORD_CWORD_CWORD_CWORD,
	/*  57   -73      */ CWORD_CWORD_CWORD_CWORD,
	/*  58   -72      */ CWORD_CWORD_CWORD_CWORD,
	/*  59   -71      */ CWORD_CWORD_CWORD_CWORD,
	/*  60   -70      */ CWORD_CWORD_CWORD_CWORD,
	/*  61   -69      */ CWORD_CWORD_CWORD_CWORD,
	/*  62   -68      */ CWORD_CWORD_CWORD_CWORD,
	/*  63   -67      */ CWORD_CWORD_CWORD_CWORD,
	/*  64   -66      */ CWORD_CWORD_CWORD_CWORD,
	/*  65   -65      */ CWORD_CWORD_CWORD_CWORD,
	/*  66   -64      */ CWORD_CWORD_CWORD_CWORD,
	/*  67   -63      */ CWORD_CWORD_CWORD_CWORD,
	/*  68   -62      */ CWORD_CWORD_CWORD_CWORD,
	/*  69   -61      */ CWORD_CWORD_CWORD_CWORD,
	/*  70   -60      */ CWORD_CWORD_CWORD_CWORD,
	/*  71   -59      */ CWORD_CWORD_CWORD_CWORD,
	/*  72   -58      */ CWORD_CWORD_CWORD_CWORD,
	/*  73   -57      */ CWORD_CWORD_CWORD_CWORD,
	/*  74   -56      */ CWORD_CWORD_CWORD_CWORD,
	/*  75   -55      */ CWORD_CWORD_CWORD_CWORD,
	/*  76   -54      */ CWORD_CWORD_CWORD_CWORD,
	/*  77   -53      */ CWORD_CWORD_CWORD_CWORD,
	/*  78   -52      */ CWORD_CWORD_CWORD_CWORD,
	/*  79   -51      */ CWORD_CWORD_CWORD_CWORD,
	/*  80   -50      */ CWORD_CWORD_CWORD_CWORD,
	/*  81   -49      */ CWORD_CWORD_CWORD_CWORD,
	/*  82   -48      */ CWORD_CWORD_CWORD_CWORD,
	/*  83   -47      */ CWORD_CWORD_CWORD_CWORD,
	/*  84   -46      */ CWORD_CWORD_CWORD_CWORD,
	/*  85   -45      */ CWORD_CWORD_CWORD_CWORD,
	/*  86   -44      */ CWORD_CWORD_CWORD_CWORD,
	/*  87   -43      */ CWORD_CWORD_CWORD_CWORD,
	/*  88   -42      */ CWORD_CWORD_CWORD_CWORD,
	/*  89   -41      */ CWORD_CWORD_CWORD_CWORD,
	/*  90   -40      */ CWORD_CWORD_CWORD_CWORD,
	/*  91   -39      */ CWORD_CWORD_CWORD_CWORD,
	/*  92   -38      */ CWORD_CWORD_CWORD_CWORD,
	/*  93   -37      */ CWORD_CWORD_CWORD_CWORD,
	/*  94   -36      */ CWORD_CWORD_CWORD_CWORD,
	/*  95   -35      */ CWORD_CWORD_CWORD_CWORD,
	/*  96   -34      */ CWORD_CWORD_CWORD_CWORD,
	/*  97   -33      */ CWORD_CWORD_CWORD_CWORD,
	/*  98   -32      */ CWORD_CWORD_CWORD_CWORD,
	/*  99   -31      */ CWORD_CWORD_CWORD_CWORD,
	/* 100   -30      */ CWORD_CWORD_CWORD_CWORD,
	/* 101   -29      */ CWORD_CWORD_CWORD_CWORD,
	/* 102   -28      */ CWORD_CWORD_CWORD_CWORD,
	/* 103   -27      */ CWORD_CWORD_CWORD_CWORD,
	/* 104   -26      */ CWORD_CWORD_CWORD_CWORD,
	/* 105   -25      */ CWORD_CWORD_CWORD_CWORD,
	/* 106   -24      */ CWORD_CWORD_CWORD_CWORD,
	/* 107   -23      */ CWORD_CWORD_CWORD_CWORD,
	/* 108   -22      */ CWORD_CWORD_CWORD_CWORD,
	/* 109   -21      */ CWORD_CWORD_CWORD_CWORD,
	/* 110   -20      */ CWORD_CWORD_CWORD_CWORD,
	/* 111   -19      */ CWORD_CWORD_CWORD_CWORD,
	/* 112   -18      */ CWORD_CWORD_CWORD_CWORD,
	/* 113   -17      */ CWORD_CWORD_CWORD_CWORD,
	/* 114   -16      */ CWORD_CWORD_CWORD_CWORD,
	/* 115   -15      */ CWORD_CWORD_CWORD_CWORD,
	/* 116   -14      */ CWORD_CWORD_CWORD_CWORD,
	/* 117   -13      */ CWORD_CWORD_CWORD_CWORD,
	/* 118   -12      */ CWORD_CWORD_CWORD_CWORD,
	/* 119   -11      */ CWORD_CWORD_CWORD_CWORD,
	/* 120   -10      */ CWORD_CWORD_CWORD_CWORD,
	/* 121    -9      */ CWORD_CWORD_CWORD_CWORD,
	/* 122    -8      */ CWORD_CWORD_CWORD_CWORD,
	/* 123    -7      */ CWORD_CWORD_CWORD_CWORD,
	/* 124    -6      */ CWORD_CWORD_CWORD_CWORD,
	/* 125    -5      */ CWORD_CWORD_CWORD_CWORD,
	/* 126    -4      */ CWORD_CWORD_CWORD_CWORD,
	/* 127    -3      */ CWORD_CWORD_CWORD_CWORD,
	/* 128    -2      */ CWORD_CWORD_CWORD_CWORD,
	/* 129    -1      */ CWORD_CWORD_CWORD_CWORD,
	/* 130     0      */ CWORD_CWORD_CWORD_CWORD,
	/* 131     1      */ CWORD_CWORD_CWORD_CWORD,
	/* 132     2      */ CWORD_CWORD_CWORD_CWORD,
	/* 133     3      */ CWORD_CWORD_CWORD_CWORD,
	/* 134     4      */ CWORD_CWORD_CWORD_CWORD,
	/* 135     5      */ CWORD_CWORD_CWORD_CWORD,
	/* 136     6      */ CWORD_CWORD_CWORD_CWORD,
	/* 137     7      */ CWORD_CWORD_CWORD_CWORD,
	/* 138     8      */ CWORD_CWORD_CWORD_CWORD,
	/* 139     9 "\t" */ CSPCL_CWORD_CWORD_CWORD,
	/* 140    10 "\n" */ CNL_CNL_CNL_CNL,
	/* 141    11      */ CWORD_CWORD_CWORD_CWORD,
	/* 142    12      */ CWORD_CWORD_CWORD_CWORD,
	/* 143    13      */ CWORD_CWORD_CWORD_CWORD,
	/* 144    14      */ CWORD_CWORD_CWORD_CWORD,
	/* 145    15      */ CWORD_CWORD_CWORD_CWORD,
	/* 146    16      */ CWORD_CWORD_CWORD_CWORD,
	/* 147    17      */ CWORD_CWORD_CWORD_CWORD,
	/* 148    18      */ CWORD_CWORD_CWORD_CWORD,
	/* 149    19      */ CWORD_CWORD_CWORD_CWORD,
	/* 150    20      */ CWORD_CWORD_CWORD_CWORD,
	/* 151    21      */ CWORD_CWORD_CWORD_CWORD,
	/* 152    22      */ CWORD_CWORD_CWORD_CWORD,
	/* 153    23      */ CWORD_CWORD_CWORD_CWORD,
	/* 154    24      */ CWORD_CWORD_CWORD_CWORD,
	/* 155    25      */ CWORD_CWORD_CWORD_CWORD,
	/* 156    26      */ CWORD_CWORD_CWORD_CWORD,
	/* 157    27      */ CWORD_CWORD_CWORD_CWORD,
	/* 158    28      */ CWORD_CWORD_CWORD_CWORD,
	/* 159    29      */ CWORD_CWORD_CWORD_CWORD,
	/* 160    30      */ CWORD_CWORD_CWORD_CWORD,
	/* 161    31      */ CWORD_CWORD_CWORD_CWORD,
	/* 162    32  " " */ CSPCL_CWORD_CWORD_CWORD,
	/* 163    33  "!" */ CWORD_CCTL_CCTL_CWORD,
	/* 164    34  """ */ CDQUOTE_CENDQUOTE_CWORD_CWORD,
	/* 165    35  "#" */ CWORD_CWORD_CWORD_CWORD,
	/* 166    36  "$" */ CVAR_CVAR_CWORD_CVAR,
	/* 167    37  "%" */ CWORD_CWORD_CWORD_CWORD,
	/* 168    38  "&" */ CSPCL_CWORD_CWORD_CWORD,
	/* 169    39  "'" */ CSQUOTE_CWORD_CENDQUOTE_CWORD,
	/* 170    40  "(" */ CSPCL_CWORD_CWORD_CLP,
	/* 171    41  ")" */ CSPCL_CWORD_CWORD_CRP,
	/* 172    42  "*" */ CWORD_CCTL_CCTL_CWORD,
	/* 173    43  "+" */ CWORD_CWORD_CWORD_CWORD,
	/* 174    44  "," */ CWORD_CWORD_CWORD_CWORD,
	/* 175    45  "-" */ CWORD_CCTL_CCTL_CWORD,
	/* 176    46  "." */ CWORD_CWORD_CWORD_CWORD,
	/* 177    47  "/" */ CWORD_CCTL_CCTL_CWORD,
	/* 178    48  "0" */ CWORD_CWORD_CWORD_CWORD,
	/* 179    49  "1" */ CWORD_CWORD_CWORD_CWORD,
	/* 180    50  "2" */ CWORD_CWORD_CWORD_CWORD,
	/* 181    51  "3" */ CWORD_CWORD_CWORD_CWORD,
	/* 182    52  "4" */ CWORD_CWORD_CWORD_CWORD,
	/* 183    53  "5" */ CWORD_CWORD_CWORD_CWORD,
	/* 184    54  "6" */ CWORD_CWORD_CWORD_CWORD,
	/* 185    55  "7" */ CWORD_CWORD_CWORD_CWORD,
	/* 186    56  "8" */ CWORD_CWORD_CWORD_CWORD,
	/* 187    57  "9" */ CWORD_CWORD_CWORD_CWORD,
	/* 188    58  ":" */ CWORD_CCTL_CCTL_CWORD,
	/* 189    59  ";" */ CSPCL_CWORD_CWORD_CWORD,
	/* 190    60  "<" */ CSPCL_CWORD_CWORD_CWORD,
	/* 191    61  "=" */ CWORD_CCTL_CCTL_CWORD,
	/* 192    62  ">" */ CSPCL_CWORD_CWORD_CWORD,
	/* 193    63  "?" */ CWORD_CCTL_CCTL_CWORD,
	/* 194    64  "@" */ CWORD_CWORD_CWORD_CWORD,
	/* 195    65  "A" */ CWORD_CWORD_CWORD_CWORD,
	/* 196    66  "B" */ CWORD_CWORD_CWORD_CWORD,
	/* 197    67  "C" */ CWORD_CWORD_CWORD_CWORD,
	/* 198    68  "D" */ CWORD_CWORD_CWORD_CWORD,
	/* 199    69  "E" */ CWORD_CWORD_CWORD_CWORD,
	/* 200    70  "F" */ CWORD_CWORD_CWORD_CWORD,
	/* 201    71  "G" */ CWORD_CWORD_CWORD_CWORD,
	/* 202    72  "H" */ CWORD_CWORD_CWORD_CWORD,
	/* 203    73  "I" */ CWORD_CWORD_CWORD_CWORD,
	/* 204    74  "J" */ CWORD_CWORD_CWORD_CWORD,
	/* 205    75  "K" */ CWORD_CWORD_CWORD_CWORD,
	/* 206    76  "L" */ CWORD_CWORD_CWORD_CWORD,
	/* 207    77  "M" */ CWORD_CWORD_CWORD_CWORD,
	/* 208    78  "N" */ CWORD_CWORD_CWORD_CWORD,
	/* 209    79  "O" */ CWORD_CWORD_CWORD_CWORD,
	/* 210    80  "P" */ CWORD_CWORD_CWORD_CWORD,
	/* 211    81  "Q" */ CWORD_CWORD_CWORD_CWORD,
	/* 212    82  "R" */ CWORD_CWORD_CWORD_CWORD,
	/* 213    83  "S" */ CWORD_CWORD_CWORD_CWORD,
	/* 214    84  "T" */ CWORD_CWORD_CWORD_CWORD,
	/* 215    85  "U" */ CWORD_CWORD_CWORD_CWORD,
	/* 216    86  "V" */ CWORD_CWORD_CWORD_CWORD,
	/* 217    87  "W" */ CWORD_CWORD_CWORD_CWORD,
	/* 218    88  "X" */ CWORD_CWORD_CWORD_CWORD,
	/* 219    89  "Y" */ CWORD_CWORD_CWORD_CWORD,
	/* 220    90  "Z" */ CWORD_CWORD_CWORD_CWORD,
	/* 221    91  "[" */ CWORD_CCTL_CCTL_CWORD,
	/* 222    92  "\" */ CBACK_CBACK_CCTL_CBACK,
	/* 223    93  "]" */ CWORD_CCTL_CCTL_CWORD,
	/* 224    94  "^" */ CWORD_CWORD_CWORD_CWORD,
	/* 225    95  "_" */ CWORD_CWORD_CWORD_CWORD,
	/* 226    96  "`" */ CBQUOTE_CBQUOTE_CWORD_CBQUOTE,
	/* 227    97  "a" */ CWORD_CWORD_CWORD_CWORD,
	/* 228    98  "b" */ CWORD_CWORD_CWORD_CWORD,
	/* 229    99  "c" */ CWORD_CWORD_CWORD_CWORD,
	/* 230   100  "d" */ CWORD_CWORD_CWORD_CWORD,
	/* 231   101  "e" */ CWORD_CWORD_CWORD_CWORD,
	/* 232   102  "f" */ CWORD_CWORD_CWORD_CWORD,
	/* 233   103  "g" */ CWORD_CWORD_CWORD_CWORD,
	/* 234   104  "h" */ CWORD_CWORD_CWORD_CWORD,
	/* 235   105  "i" */ CWORD_CWORD_CWORD_CWORD,
	/* 236   106  "j" */ CWORD_CWORD_CWORD_CWORD,
	/* 237   107  "k" */ CWORD_CWORD_CWORD_CWORD,
	/* 238   108  "l" */ CWORD_CWORD_CWORD_CWORD,
	/* 239   109  "m" */ CWORD_CWORD_CWORD_CWORD,
	/* 240   110  "n" */ CWORD_CWORD_CWORD_CWORD,
	/* 241   111  "o" */ CWORD_CWORD_CWORD_CWORD,
	/* 242   112  "p" */ CWORD_CWORD_CWORD_CWORD,
	/* 243   113  "q" */ CWORD_CWORD_CWORD_CWORD,
	/* 244   114  "r" */ CWORD_CWORD_CWORD_CWORD,
	/* 245   115  "s" */ CWORD_CWORD_CWORD_CWORD,
	/* 246   116  "t" */ CWORD_CWORD_CWORD_CWORD,
	/* 247   117  "u" */ CWORD_CWORD_CWORD_CWORD,
	/* 248   118  "v" */ CWORD_CWORD_CWORD_CWORD,
	/* 249   119  "w" */ CWORD_CWORD_CWORD_CWORD,
	/* 250   120  "x" */ CWORD_CWORD_CWORD_CWORD,
	/* 251   121  "y" */ CWORD_CWORD_CWORD_CWORD,
	/* 252   122  "z" */ CWORD_CWORD_CWORD_CWORD,
	/* 253   123  "{" */ CWORD_CWORD_CWORD_CWORD,
	/* 254   124  "|" */ CSPCL_CWORD_CWORD_CWORD,
	/* 255   125  "}" */ CENDVAR_CENDVAR_CWORD_CENDVAR,
	/* 256   126  "~" */ CWORD_CCTL_CCTL_CWORD,
	/* 257   127      */ CWORD_CWORD_CWORD_CWORD,
};

#define SIT(c, syntax) (S_I_T[(int)syntax_index_table[((int)c)+SYNBASE]][syntax])

#endif  /* USE_SIT_FUNCTION */


/* ============ Alias handling */

#if ENABLE_ASH_ALIAS

#define ALIASINUSE 1
#define ALIASDEAD  2

#define ATABSIZE 39

struct alias {
	struct alias *next;
	char *name;
	char *val;
	int flag;
};

static struct alias *atab[ATABSIZE];

static struct alias **
__lookupalias(const char *name) {
	unsigned int hashval;
	struct alias **app;
	const char *p;
	unsigned int ch;

	p = name;

	ch = (unsigned char)*p;
	hashval = ch << 4;
	while (ch) {
		hashval += ch;
		ch = (unsigned char)*++p;
	}
	app = &atab[hashval % ATABSIZE];

	for (; *app; app = &(*app)->next) {
		if (strcmp(name, (*app)->name) == 0) {
			break;
		}
	}

	return app;
}

static struct alias *
lookupalias(const char *name, int check)
{
	struct alias *ap = *__lookupalias(name);

	if (check && ap && (ap->flag & ALIASINUSE))
		return NULL;
	return ap;
}

static struct alias *
freealias(struct alias *ap)
{
	struct alias *next;

	if (ap->flag & ALIASINUSE) {
		ap->flag |= ALIASDEAD;
		return ap;
	}

	next = ap->next;
	free(ap->name);
	free(ap->val);
	free(ap);
	return next;
}

static void
setalias(const char *name, const char *val)
{
	struct alias *ap, **app;

	app = __lookupalias(name);
	ap = *app;
	INT_OFF;
	if (ap) {
		if (!(ap->flag & ALIASINUSE)) {
			free(ap->val);
		}
		ap->val = ckstrdup(val);
		ap->flag &= ~ALIASDEAD;
	} else {
		/* not found */
		ap = ckmalloc(sizeof(struct alias));
		ap->name = ckstrdup(name);
		ap->val = ckstrdup(val);
		ap->flag = 0;
		ap->next = 0;
		*app = ap;
	}
	INT_ON;
}

static int
unalias(const char *name)
{
	struct alias **app;

	app = __lookupalias(name);

	if (*app) {
		INT_OFF;
		*app = freealias(*app);
		INT_ON;
		return 0;
	}

	return 1;
}

static void
rmaliases(void)
{
	struct alias *ap, **app;
	int i;

	INT_OFF;
	for (i = 0; i < ATABSIZE; i++) {
		app = &atab[i];
		for (ap = *app; ap; ap = *app) {
			*app = freealias(*app);
			if (ap == *app) {
				app = &ap->next;
			}
		}
	}
	INT_ON;
}

static void
printalias(const struct alias *ap)
{
	out1fmt("%s=%s\n", ap->name, single_quote(ap->val));
}

/*
 * TODO - sort output
 */
static int
aliascmd(int argc, char **argv)
{
	char *n, *v;
	int ret = 0;
	struct alias *ap;

	if (argc == 1) {
		int i;

		for (i = 0; i < ATABSIZE; i++)
			for (ap = atab[i]; ap; ap = ap->next) {
				printalias(ap);
			}
		return 0;
	}
	while ((n = *++argv) != NULL) {
		v = strchr(n+1, '=');
		if (v == NULL) { /* n+1: funny ksh stuff */
			ap = *__lookupalias(n);
			if (ap == NULL) {
				fprintf(stderr, "%s: %s not found\n", "alias", n);
				ret = 1;
			} else
				printalias(ap);
		} else {
			*v++ = '\0';
			setalias(n, v);
		}
	}

	return ret;
}

static int
unaliascmd(int argc, char **argv)
{
	int i;

	while ((i = nextopt("a")) != '\0') {
		if (i == 'a') {
			rmaliases();
			return 0;
		}
	}
	for (i = 0; *argptr; argptr++) {
		if (unalias(*argptr)) {
			fprintf(stderr, "%s: %s not found\n", "unalias", *argptr);
			i = 1;
		}
	}

	return i;
}

#endif /* ASH_ALIAS */


/* ============ jobs.c */

/* Mode argument to forkshell.  Don't change FORK_FG or FORK_BG. */
#define FORK_FG 0
#define FORK_BG 1
#define FORK_NOJOB 2

/* mode flags for showjob(s) */
#define SHOW_PGID       0x01    /* only show pgid - for jobs -p */
#define SHOW_PID        0x04    /* include process pid */
#define SHOW_CHANGED    0x08    /* only jobs whose state has changed */

/*
 * A job structure contains information about a job.  A job is either a
 * single process or a set of processes contained in a pipeline.  In the
 * latter case, pidlist will be non-NULL, and will point to a -1 terminated
 * array of pids.
 */

struct procstat {
	pid_t   pid;            /* process id */
	int     status;         /* last process status from wait() */
	char    *cmd;           /* text of command being run */
};

struct job {
	struct procstat ps0;    /* status of process */
	struct procstat *ps;    /* status or processes when more than one */
#if JOBS
	int stopstatus;         /* status of a stopped job */
#endif
	uint32_t
		nprocs: 16,     /* number of processes */
		state: 8,
#define JOBRUNNING      0       /* at least one proc running */
#define JOBSTOPPED      1       /* all procs are stopped */
#define JOBDONE         2       /* all procs are completed */
#if JOBS
		sigint: 1,      /* job was killed by SIGINT */
		jobctl: 1,      /* job running under job control */
#endif
		waited: 1,      /* true if this entry has been waited for */
		used: 1,        /* true if this entry is in used */
		changed: 1;     /* true if status has changed */
	struct job *prev_job;   /* previous job */
};

static pid_t backgndpid;        /* pid of last background process */
static int job_warning;         /* user was warned about stopped jobs */
#if JOBS
static int jobctl;              /* true if doing job control */
#endif

static struct job *makejob(union node *, int);
static int forkshell(struct job *, union node *, int);
static int waitforjob(struct job *);

#if ! JOBS
#define setjobctl(on)   /* do nothing */
#else
static void setjobctl(int);
static void showjobs(FILE *, int);
#endif

/*
 * Set the signal handler for the specified signal.  The routine figures
 * out what it should be set to.
 */
static void
setsignal(int signo)
{
	int action;
	char *t, tsig;
	struct sigaction act;

	t = trap[signo];
	if (t == NULL)
		action = S_DFL;
	else if (*t != '\0')
		action = S_CATCH;
	else
		action = S_IGN;
	if (rootshell && action == S_DFL) {
		switch (signo) {
		case SIGINT:
			if (iflag || minusc || sflag == 0)
				action = S_CATCH;
			break;
		case SIGQUIT:
#if DEBUG
			if (debug)
				break;
#endif
			/* FALLTHROUGH */
		case SIGTERM:
			if (iflag)
				action = S_IGN;
			break;
#if JOBS
		case SIGTSTP:
		case SIGTTOU:
			if (mflag)
				action = S_IGN;
			break;
#endif
		}
	}

	t = &sigmode[signo - 1];
	tsig = *t;
	if (tsig == 0) {
		/*
		 * current setting unknown
		 */
		if (sigaction(signo, 0, &act) == -1) {
			/*
			 * Pretend it worked; maybe we should give a warning
			 * here, but other shells don't. We don't alter
			 * sigmode, so that we retry every time.
			 */
			return;
		}
		if (act.sa_handler == SIG_IGN) {
			if (mflag
			 && (signo == SIGTSTP || signo == SIGTTIN || signo == SIGTTOU)
			) {
				tsig = S_IGN;   /* don't hard ignore these */
			} else
				tsig = S_HARD_IGN;
		} else {
			tsig = S_RESET; /* force to be set */
		}
	}
	if (tsig == S_HARD_IGN || tsig == action)
		return;
	switch (action) {
	case S_CATCH:
		act.sa_handler = onsig;
		break;
	case S_IGN:
		act.sa_handler = SIG_IGN;
		break;
	default:
		act.sa_handler = SIG_DFL;
	}
	*t = action;
	act.sa_flags = 0;
	sigfillset(&act.sa_mask);
	sigaction(signo, &act, 0);
}

/* mode flags for set_curjob */
#define CUR_DELETE 2
#define CUR_RUNNING 1
#define CUR_STOPPED 0

/* mode flags for dowait */
#define DOWAIT_NORMAL 0
#define DOWAIT_BLOCK 1

#if JOBS
/* pgrp of shell on invocation */
static int initialpgrp;
static int ttyfd = -1;
#endif
/* array of jobs */
static struct job *jobtab;
/* size of array */
static unsigned njobs;
/* current job */
static struct job *curjob;
/* number of presumed living untracked jobs */
static int jobless;

static void
set_curjob(struct job *jp, unsigned mode)
{
	struct job *jp1;
	struct job **jpp, **curp;

	/* first remove from list */
	jpp = curp = &curjob;
	do {
		jp1 = *jpp;
		if (jp1 == jp)
			break;
		jpp = &jp1->prev_job;
	} while (1);
	*jpp = jp1->prev_job;

	/* Then re-insert in correct position */
	jpp = curp;
	switch (mode) {
	default:
#if DEBUG
		abort();
#endif
	case CUR_DELETE:
		/* job being deleted */
		break;
	case CUR_RUNNING:
		/* newly created job or backgrounded job,
		   put after all stopped jobs. */
		do {
			jp1 = *jpp;
#if JOBS
			if (!jp1 || jp1->state != JOBSTOPPED)
#endif
				break;
			jpp = &jp1->prev_job;
		} while (1);
		/* FALLTHROUGH */
#if JOBS
	case CUR_STOPPED:
#endif
		/* newly stopped job - becomes curjob */
		jp->prev_job = *jpp;
		*jpp = jp;
		break;
	}
}

#if JOBS || DEBUG
static int
jobno(const struct job *jp)
{
	return jp - jobtab + 1;
}
#endif

/*
 * Convert a job name to a job structure.
 */
static struct job *
getjob(const char *name, int getctl)
{
	struct job *jp;
	struct job *found;
	const char *err_msg = "No such job: %s";
	unsigned num;
	int c;
	const char *p;
	char *(*match)(const char *, const char *);

	jp = curjob;
	p = name;
	if (!p)
		goto currentjob;

	if (*p != '%')
		goto err;

	c = *++p;
	if (!c)
		goto currentjob;

	if (!p[1]) {
		if (c == '+' || c == '%') {
 currentjob:
			err_msg = "No current job";
			goto check;
		}
		if (c == '-') {
			if (jp)
				jp = jp->prev_job;
			err_msg = "No previous job";
 check:
			if (!jp)
				goto err;
			goto gotit;
		}
	}

	if (is_number(p)) {
		num = atoi(p);
		if (num < njobs) {
			jp = jobtab + num - 1;
			if (jp->used)
				goto gotit;
			goto err;
		}
	}

	match = prefix;
	if (*p == '?') {
		match = strstr;
		p++;
	}

	found = 0;
	while (1) {
		if (!jp)
			goto err;
		if (match(jp->ps[0].cmd, p)) {
			if (found)
				goto err;
			found = jp;
			err_msg = "%s: ambiguous";
		}
		jp = jp->prev_job;
	}

 gotit:
#if JOBS
	err_msg = "job %s not created under job control";
	if (getctl && jp->jobctl == 0)
		goto err;
#endif
	return jp;
 err:
	ash_msg_and_raise_error(err_msg, name);
}

/*
 * Mark a job structure as unused.
 */
static void
freejob(struct job *jp)
{
	struct procstat *ps;
	int i;

	INT_OFF;
	for (i = jp->nprocs, ps = jp->ps; --i >= 0; ps++) {
		if (ps->cmd != nullstr)
			free(ps->cmd);
	}
	if (jp->ps != &jp->ps0)
		free(jp->ps);
	jp->used = 0;
	set_curjob(jp, CUR_DELETE);
	INT_ON;
}

#if JOBS
static void
xtcsetpgrp(int fd, pid_t pgrp)
{
	if (tcsetpgrp(fd, pgrp))
		ash_msg_and_raise_error("cannot set tty process group (%m)");
}

/*
 * Turn job control on and off.
 *
 * Note:  This code assumes that the third arg to ioctl is a character
 * pointer, which is true on Berkeley systems but not System V.  Since
 * System V doesn't have job control yet, this isn't a problem now.
 *
 * Called with interrupts off.
 */
static void
setjobctl(int on)
{
	int fd;
	int pgrp;

	if (on == jobctl || rootshell == 0)
		return;
	if (on) {
		int ofd;
		ofd = fd = open(_PATH_TTY, O_RDWR);
		if (fd < 0) {
	/* BTW, bash will try to open(ttyname(0)) if open("/dev/tty") fails.
	 * That sometimes helps to acquire controlling tty.
	 * Obviously, a workaround for bugs when someone
	 * failed to provide a controlling tty to bash! :) */
			fd += 3;
			while (!isatty(fd) && --fd >= 0)
				;
		}
		fd = fcntl(fd, F_DUPFD, 10);
		close(ofd);
		if (fd < 0)
			goto out;
		fcntl(fd, F_SETFD, FD_CLOEXEC);
		do { /* while we are in the background */
			pgrp = tcgetpgrp(fd);
			if (pgrp < 0) {
 out:
				ash_msg("can't access tty; job control turned off");
				mflag = on = 0;
				goto close;
			}
			if (pgrp == getpgrp())
				break;
			killpg(0, SIGTTIN);
		} while (1);
		initialpgrp = pgrp;

		setsignal(SIGTSTP);
		setsignal(SIGTTOU);
		setsignal(SIGTTIN);
		pgrp = rootpid;
		setpgid(0, pgrp);
		xtcsetpgrp(fd, pgrp);
	} else {
		/* turning job control off */
		fd = ttyfd;
		pgrp = initialpgrp;
		xtcsetpgrp(fd, pgrp);
		setpgid(0, pgrp);
		setsignal(SIGTSTP);
		setsignal(SIGTTOU);
		setsignal(SIGTTIN);
 close:
		close(fd);
		fd = -1;
	}
	ttyfd = fd;
	jobctl = on;
}

static int
killcmd(int argc, char **argv)
{
	int signo = -1;
	int list = 0;
	int i;
	pid_t pid;
	struct job *jp;

	if (argc <= 1) {
 usage:
		ash_msg_and_raise_error(
"usage: kill [-s sigspec | -signum | -sigspec] [pid | job]... or\n"
"kill -l [exitstatus]"
		);
	}

	if (**++argv == '-') {
		signo = get_signum(*argv + 1);
		if (signo < 0) {
			int c;

			while ((c = nextopt("ls:")) != '\0') {
				switch (c) {
				default:
#if DEBUG
					abort();
#endif
				case 'l':
					list = 1;
					break;
				case 's':
					signo = get_signum(optionarg);
					if (signo < 0) {
						ash_msg_and_raise_error(
							"invalid signal number or name: %s",
							optionarg
						);
					}
					break;
				}
			}
			argv = argptr;
		} else
			argv++;
	}

	if (!list && signo < 0)
		signo = SIGTERM;

	if ((signo < 0 || !*argv) ^ list) {
		goto usage;
	}

	if (list) {
		const char *name;

		if (!*argv) {
			for (i = 1; i < NSIG; i++) {
				name = get_signame(i);
				if (isdigit(*name))
					out1fmt(snlfmt, name);
			}
			return 0;
		}
		name = get_signame(signo);
		if (!isdigit(*name))
			ash_msg_and_raise_error("invalid signal number or exit status: %s", *argptr);
		out1fmt(snlfmt, name);
		return 0;
	}

	i = 0;
	do {
		if (**argv == '%') {
			jp = getjob(*argv, 0);
			pid = -jp->ps[0].pid;
		} else {
			pid = **argv == '-' ?
				-number(*argv + 1) : number(*argv);
		}
		if (kill(pid, signo) != 0) {
			ash_msg("(%d) - %m", pid);
			i = 1;
		}
	} while (*++argv);

	return i;
}

static void
showpipe(struct job *jp, FILE *out)
{
	struct procstat *sp;
	struct procstat *spend;

	spend = jp->ps + jp->nprocs;
	for (sp = jp->ps + 1; sp < spend; sp++)
		fprintf(out, " | %s", sp->cmd);
	outcslow('\n', out);
	flush_stdout_stderr();
}


static int
restartjob(struct job *jp, int mode)
{
	struct procstat *ps;
	int i;
	int status;
	pid_t pgid;

	INT_OFF;
	if (jp->state == JOBDONE)
		goto out;
	jp->state = JOBRUNNING;
	pgid = jp->ps->pid;
	if (mode == FORK_FG)
		xtcsetpgrp(ttyfd, pgid);
	killpg(pgid, SIGCONT);
	ps = jp->ps;
	i = jp->nprocs;
	do {
		if (WIFSTOPPED(ps->status)) {
			ps->status = -1;
		}
	} while (ps++, --i);
 out:
	status = (mode == FORK_FG) ? waitforjob(jp) : 0;
	INT_ON;
	return status;
}

static int
fg_bgcmd(int argc, char **argv)
{
	struct job *jp;
	FILE *out;
	int mode;
	int retval;

	mode = (**argv == 'f') ? FORK_FG : FORK_BG;
	nextopt(nullstr);
	argv = argptr;
	out = stdout;
	do {
		jp = getjob(*argv, 1);
		if (mode == FORK_BG) {
			set_curjob(jp, CUR_RUNNING);
			fprintf(out, "[%d] ", jobno(jp));
		}
		outstr(jp->ps->cmd, out);
		showpipe(jp, out);
		retval = restartjob(jp, mode);
	} while (*argv && *++argv);
	return retval;
}
#endif

static int
sprint_status(char *s, int status, int sigonly)
{
	int col;
	int st;

	col = 0;
	if (!WIFEXITED(status)) {
#if JOBS
		if (WIFSTOPPED(status))
			st = WSTOPSIG(status);
		else
#endif
			st = WTERMSIG(status);
		if (sigonly) {
			if (st == SIGINT || st == SIGPIPE)
				goto out;
#if JOBS
			if (WIFSTOPPED(status))
				goto out;
#endif
		}
		st &= 0x7f;
		col = fmtstr(s, 32, strsignal(st));
		if (WCOREDUMP(status)) {
			col += fmtstr(s + col, 16, " (core dumped)");
		}
	} else if (!sigonly) {
		st = WEXITSTATUS(status);
		if (st)
			col = fmtstr(s, 16, "Done(%d)", st);
		else
			col = fmtstr(s, 16, "Done");
	}
 out:
	return col;
}

/*
 * Do a wait system call.  If job control is compiled in, we accept
 * stopped processes.  If block is zero, we return a value of zero
 * rather than blocking.
 *
 * System V doesn't have a non-blocking wait system call.  It does
 * have a SIGCLD signal that is sent to a process when one of it's
 * children dies.  The obvious way to use SIGCLD would be to install
 * a handler for SIGCLD which simply bumped a counter when a SIGCLD
 * was received, and have waitproc bump another counter when it got
 * the status of a process.  Waitproc would then know that a wait
 * system call would not block if the two counters were different.
 * This approach doesn't work because if a process has children that
 * have not been waited for, System V will send it a SIGCLD when it
 * installs a signal handler for SIGCLD.  What this means is that when
 * a child exits, the shell will be sent SIGCLD signals continuously
 * until is runs out of stack space, unless it does a wait call before
 * restoring the signal handler.  The code below takes advantage of
 * this (mis)feature by installing a signal handler for SIGCLD and
 * then checking to see whether it was called.  If there are any
 * children to be waited for, it will be.
 *
 * If neither SYSV nor BSD is defined, we don't implement nonblocking
 * waits at all.  In this case, the user will not be informed when
 * a background process until the next time she runs a real program
 * (as opposed to running a builtin command or just typing return),
 * and the jobs command may give out of date information.
 */
static int
waitproc(int block, int *status)
{
	int flags = 0;

#if JOBS
	if (jobctl)
		flags |= WUNTRACED;
#endif
	if (block == 0)
		flags |= WNOHANG;
	return wait3(status, flags, (struct rusage *)NULL);
}

/*
 * Wait for a process to terminate.
 */
static int
dowait(int block, struct job *job)
{
	int pid;
	int status;
	struct job *jp;
	struct job *thisjob;
	int state;

	TRACE(("dowait(%d) called\n", block));
	pid = waitproc(block, &status);
	TRACE(("wait returns pid %d, status=%d\n", pid, status));
	if (pid <= 0)
		return pid;
	INT_OFF;
	thisjob = NULL;
	for (jp = curjob; jp; jp = jp->prev_job) {
		struct procstat *sp;
		struct procstat *spend;
		if (jp->state == JOBDONE)
			continue;
		state = JOBDONE;
		spend = jp->ps + jp->nprocs;
		sp = jp->ps;
		do {
			if (sp->pid == pid) {
				TRACE(("Job %d: changing status of proc %d "
					"from 0x%x to 0x%x\n",
					jobno(jp), pid, sp->status, status));
				sp->status = status;
				thisjob = jp;
			}
			if (sp->status == -1)
				state = JOBRUNNING;
#if JOBS
			if (state == JOBRUNNING)
				continue;
			if (WIFSTOPPED(sp->status)) {
				jp->stopstatus = sp->status;
				state = JOBSTOPPED;
			}
#endif
		} while (++sp < spend);
		if (thisjob)
			goto gotjob;
	}
#if JOBS
	if (!WIFSTOPPED(status))
#endif

		jobless--;
	goto out;

 gotjob:
	if (state != JOBRUNNING) {
		thisjob->changed = 1;

		if (thisjob->state != state) {
			TRACE(("Job %d: changing state from %d to %d\n",
				jobno(thisjob), thisjob->state, state));
			thisjob->state = state;
#if JOBS
			if (state == JOBSTOPPED) {
				set_curjob(thisjob, CUR_STOPPED);
			}
#endif
		}
	}

 out:
	INT_ON;

	if (thisjob && thisjob == job) {
		char s[48 + 1];
		int len;

		len = sprint_status(s, status, 1);
		if (len) {
			s[len] = '\n';
			s[len + 1] = 0;
			out2str(s);
		}
	}
	return pid;
}

#if JOBS
static void
showjob(FILE *out, struct job *jp, int mode)
{
	struct procstat *ps;
	struct procstat *psend;
	int col;
	int indent;
	char s[80];

	ps = jp->ps;

	if (mode & SHOW_PGID) {
		/* just output process (group) id of pipeline */
		fprintf(out, "%d\n", ps->pid);
		return;
	}

	col = fmtstr(s, 16, "[%d]   ", jobno(jp));
	indent = col;

	if (jp == curjob)
		s[col - 2] = '+';
	else if (curjob && jp == curjob->prev_job)
		s[col - 2] = '-';

	if (mode & SHOW_PID)
		col += fmtstr(s + col, 16, "%d ", ps->pid);

	psend = ps + jp->nprocs;

	if (jp->state == JOBRUNNING) {
		strcpy(s + col, "Running");
		col += sizeof("Running") - 1;
	} else {
		int status = psend[-1].status;
		if (jp->state == JOBSTOPPED)
			status = jp->stopstatus;
		col += sprint_status(s + col, status, 0);
	}

	goto start;

	do {
		/* for each process */
		col = fmtstr(s, 48, " |\n%*c%d ", indent, ' ', ps->pid) - 3;
 start:
		fprintf(out, "%s%*c%s",
			s, 33 - col >= 0 ? 33 - col : 0, ' ', ps->cmd
		);
		if (!(mode & SHOW_PID)) {
			showpipe(jp, out);
			break;
		}
		if (++ps == psend) {
			outcslow('\n', out);
			break;
		}
	} while (1);

	jp->changed = 0;

	if (jp->state == JOBDONE) {
		TRACE(("showjob: freeing job %d\n", jobno(jp)));
		freejob(jp);
	}
}

static int
jobscmd(int argc, char **argv)
{
	int mode, m;
	FILE *out;

	mode = 0;
	while ((m = nextopt("lp"))) {
		if (m == 'l')
			mode = SHOW_PID;
		else
			mode = SHOW_PGID;
	}

	out = stdout;
	argv = argptr;
	if (*argv) {
		do
			showjob(out, getjob(*argv,0), mode);
		while (*++argv);
	} else
		showjobs(out, mode);

	return 0;
}

/*
 * Print a list of jobs.  If "change" is nonzero, only print jobs whose
 * statuses have changed since the last call to showjobs.
 */
static void
showjobs(FILE *out, int mode)
{
	struct job *jp;

	TRACE(("showjobs(%x) called\n", mode));

	/* If not even one one job changed, there is nothing to do */
	while (dowait(DOWAIT_NORMAL, NULL) > 0)
		continue;

	for (jp = curjob; jp; jp = jp->prev_job) {
		if (!(mode & SHOW_CHANGED) || jp->changed)
			showjob(out, jp, mode);
	}
}
#endif /* JOBS */

static int
getstatus(struct job *job)
{
	int status;
	int retval;

	status = job->ps[job->nprocs - 1].status;
	retval = WEXITSTATUS(status);
	if (!WIFEXITED(status)) {
#if JOBS
		retval = WSTOPSIG(status);
		if (!WIFSTOPPED(status))
#endif
		{
			/* XXX: limits number of signals */
			retval = WTERMSIG(status);
#if JOBS
			if (retval == SIGINT)
				job->sigint = 1;
#endif
		}
		retval += 128;
	}
	TRACE(("getstatus: job %d, nproc %d, status %x, retval %x\n",
		jobno(job), job->nprocs, status, retval));
	return retval;
}

static int
waitcmd(int argc, char **argv)
{
	struct job *job;
	int retval;
	struct job *jp;

	EXSIGON;

	nextopt(nullstr);
	retval = 0;

	argv = argptr;
	if (!*argv) {
		/* wait for all jobs */
		for (;;) {
			jp = curjob;
			while (1) {
				if (!jp) {
					/* no running procs */
					goto out;
				}
				if (jp->state == JOBRUNNING)
					break;
				jp->waited = 1;
				jp = jp->prev_job;
			}
			dowait(DOWAIT_BLOCK, 0);
		}
	}

	retval = 127;
	do {
		if (**argv != '%') {
			pid_t pid = number(*argv);
			job = curjob;
			goto start;
			do {
				if (job->ps[job->nprocs - 1].pid == pid)
					break;
				job = job->prev_job;
 start:
				if (!job)
					goto repeat;
			} while (1);
		} else
			job = getjob(*argv, 0);
		/* loop until process terminated or stopped */
		while (job->state == JOBRUNNING)
			dowait(DOWAIT_BLOCK, 0);
		job->waited = 1;
		retval = getstatus(job);
 repeat:
		;
	} while (*++argv);

 out:
	return retval;
}

static struct job *
growjobtab(void)
{
	size_t len;
	ptrdiff_t offset;
	struct job *jp, *jq;

	len = njobs * sizeof(*jp);
	jq = jobtab;
	jp = ckrealloc(jq, len + 4 * sizeof(*jp));

	offset = (char *)jp - (char *)jq;
	if (offset) {
		/* Relocate pointers */
		size_t l = len;

		jq = (struct job *)((char *)jq + l);
		while (l) {
			l -= sizeof(*jp);
			jq--;
#define joff(p) ((struct job *)((char *)(p) + l))
#define jmove(p) (p) = (void *)((char *)(p) + offset)
			if (joff(jp)->ps == &jq->ps0)
				jmove(joff(jp)->ps);
			if (joff(jp)->prev_job)
				jmove(joff(jp)->prev_job);
		}
		if (curjob)
			jmove(curjob);
#undef joff
#undef jmove
	}

	njobs += 4;
	jobtab = jp;
	jp = (struct job *)((char *)jp + len);
	jq = jp + 3;
	do {
		jq->used = 0;
	} while (--jq >= jp);
	return jp;
}

/*
 * Return a new job structure.
 * Called with interrupts off.
 */
static struct job *
makejob(union node *node, int nprocs)
{
	int i;
	struct job *jp;

	for (i = njobs, jp = jobtab; ; jp++) {
		if (--i < 0) {
			jp = growjobtab();
			break;
		}
		if (jp->used == 0)
			break;
		if (jp->state != JOBDONE || !jp->waited)
			continue;
#if JOBS
		if (jobctl)
			continue;
#endif
		freejob(jp);
		break;
	}
	memset(jp, 0, sizeof(*jp));
#if JOBS
	if (jobctl)
		jp->jobctl = 1;
#endif
	jp->prev_job = curjob;
	curjob = jp;
	jp->used = 1;
	jp->ps = &jp->ps0;
	if (nprocs > 1) {
		jp->ps = ckmalloc(nprocs * sizeof(struct procstat));
	}
	TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs,
				jobno(jp)));
	return jp;
}

#if JOBS
/*
 * Return a string identifying a command (to be printed by the
 * jobs command).
 */
static char *cmdnextc;

static void
cmdputs(const char *s)
{
	const char *p, *str;
	char c, cc[2] = " ";
	char *nextc;
	int subtype = 0;
	int quoted = 0;
	static const char vstype[VSTYPE + 1][4] = {
		"", "}", "-", "+", "?", "=",
		"%", "%%", "#", "##"
	};

	nextc = makestrspace((strlen(s) + 1) * 8, cmdnextc);
	p = s;
	while ((c = *p++) != 0) {
		str = 0;
		switch (c) {
		case CTLESC:
			c = *p++;
			break;
		case CTLVAR:
			subtype = *p++;
			if ((subtype & VSTYPE) == VSLENGTH)
				str = "${#";
			else
				str = "${";
			if (!(subtype & VSQUOTE) == !(quoted & 1))
				goto dostr;
			quoted ^= 1;
			c = '"';
			break;
		case CTLENDVAR:
			str = "\"}" + !(quoted & 1);
			quoted >>= 1;
			subtype = 0;
			goto dostr;
		case CTLBACKQ:
			str = "$(...)";
			goto dostr;
		case CTLBACKQ+CTLQUOTE:
			str = "\"$(...)\"";
			goto dostr;
#if ENABLE_ASH_MATH_SUPPORT
		case CTLARI:
			str = "$((";
			goto dostr;
		case CTLENDARI:
			str = "))";
			goto dostr;
#endif
		case CTLQUOTEMARK:
			quoted ^= 1;
			c = '"';
			break;
		case '=':
			if (subtype == 0)
				break;
			if ((subtype & VSTYPE) != VSNORMAL)
				quoted <<= 1;
			str = vstype[subtype & VSTYPE];
			if (subtype & VSNUL)
				c = ':';
			else
				goto checkstr;
			break;
		case '\'':
		case '\\':
		case '"':
		case '$':
			/* These can only happen inside quotes */
			cc[0] = c;
			str = cc;
			c = '\\';
			break;
		default:
			break;
		}
		USTPUTC(c, nextc);
 checkstr:
		if (!str)
			continue;
 dostr:
		while ((c = *str++)) {
			USTPUTC(c, nextc);
		}
	}
	if (quoted & 1) {
		USTPUTC('"', nextc);
	}
	*nextc = 0;
	cmdnextc = nextc;
}

/* cmdtxt() and cmdlist() call each other */
static void cmdtxt(union node *n);

static void
cmdlist(union node *np, int sep)
{
	for (; np; np = np->narg.next) {
		if (!sep)
			cmdputs(" ");
		cmdtxt(np);
		if (sep && np->narg.next)
			cmdputs(" ");
	}
}

static void
cmdtxt(union node *n)
{
	union node *np;
	struct nodelist *lp;
	const char *p;
	char s[2];

	if (!n)
		return;
	switch (n->type) {
	default:
#if DEBUG
		abort();
#endif
	case NPIPE:
		lp = n->npipe.cmdlist;
		for (;;) {
			cmdtxt(lp->n);
			lp = lp->next;
			if (!lp)
				break;
			cmdputs(" | ");
		}
		break;
	case NSEMI:
		p = "; ";
		goto binop;
	case NAND:
		p = " && ";
		goto binop;
	case NOR:
		p = " || ";
 binop:
		cmdtxt(n->nbinary.ch1);
		cmdputs(p);
		n = n->nbinary.ch2;
		goto donode;
	case NREDIR:
	case NBACKGND:
		n = n->nredir.n;
		goto donode;
	case NNOT:
		cmdputs("!");
		n = n->nnot.com;
 donode:
		cmdtxt(n);
		break;
	case NIF:
		cmdputs("if ");
		cmdtxt(n->nif.test);
		cmdputs("; then ");
		n = n->nif.ifpart;
		if (n->nif.elsepart) {
			cmdtxt(n);
			cmdputs("; else ");
			n = n->nif.elsepart;
		}
		p = "; fi";
		goto dotail;
	case NSUBSHELL:
		cmdputs("(");
		n = n->nredir.n;
		p = ")";
		goto dotail;
	case NWHILE:
		p = "while ";
		goto until;
	case NUNTIL:
		p = "until ";
 until:
		cmdputs(p);
		cmdtxt(n->nbinary.ch1);
		n = n->nbinary.ch2;
		p = "; done";
 dodo:
		cmdputs("; do ");
 dotail:
		cmdtxt(n);
		goto dotail2;
	case NFOR:
		cmdputs("for ");
		cmdputs(n->nfor.var);
		cmdputs(" in ");
		cmdlist(n->nfor.args, 1);
		n = n->nfor.body;
		p = "; done";
		goto dodo;
	case NDEFUN:
		cmdputs(n->narg.text);
		p = "() { ... }";
		goto dotail2;
	case NCMD:
		cmdlist(n->ncmd.args, 1);
		cmdlist(n->ncmd.redirect, 0);
		break;
	case NARG:
		p = n->narg.text;
 dotail2:
		cmdputs(p);
		break;
	case NHERE:
	case NXHERE:
		p = "<<...";
		goto dotail2;
	case NCASE:
		cmdputs("case ");
		cmdputs(n->ncase.expr->narg.text);
		cmdputs(" in ");
		for (np = n->ncase.cases; np; np = np->nclist.next) {
			cmdtxt(np->nclist.pattern);
			cmdputs(") ");
			cmdtxt(np->nclist.body);
			cmdputs(";; ");
		}
		p = "esac";
		goto dotail2;
	case NTO:
		p = ">";
		goto redir;
	case NCLOBBER:
		p = ">|";
		goto redir;
	case NAPPEND:
		p = ">>";
		goto redir;
	case NTOFD:
		p = ">&";
		goto redir;
	case NFROM:
		p = "<";
		goto redir;
	case NFROMFD:
		p = "<&";
		goto redir;
	case NFROMTO:
		p = "<>";
 redir:
		s[0] = n->nfile.fd + '0';
		s[1] = '\0';
		cmdputs(s);
		cmdputs(p);
		if (n->type == NTOFD || n->type == NFROMFD) {
			s[0] = n->ndup.dupfd + '0';
			p = s;
			goto dotail2;
		}
		n = n->nfile.fname;
		goto donode;
	}
}

static char *
commandtext(union node *n)
{
	char *name;

	STARTSTACKSTR(cmdnextc);
	cmdtxt(n);
	name = stackblock();
	TRACE(("commandtext: name %p, end %p\n\t\"%s\"\n",
			name, cmdnextc, cmdnextc));
	return ckstrdup(name);
}
#endif /* JOBS */

/*
 * Fork off a subshell.  If we are doing job control, give the subshell its
 * own process group.  Jp is a job structure that the job is to be added to.
 * N is the command that will be evaluated by the child.  Both jp and n may
 * be NULL.  The mode parameter can be one of the following:
 *      FORK_FG - Fork off a foreground process.
 *      FORK_BG - Fork off a background process.
 *      FORK_NOJOB - Like FORK_FG, but don't give the process its own
 *                   process group even if job control is on.
 *
 * When job control is turned off, background processes have their standard
 * input redirected to /dev/null (except for the second and later processes
 * in a pipeline).
 *
 * Called with interrupts off.
 */
/*
 * Clear traps on a fork.
 */
static void
clear_traps(void)
{
	char **tp;

	for (tp = trap; tp < &trap[NSIG]; tp++) {
		if (*tp && **tp) {      /* trap not NULL or SIG_IGN */
			INT_OFF;
			free(*tp);
			*tp = NULL;
			if (tp != &trap[0])
				setsignal(tp - trap);
			INT_ON;
		}
	}
}
/* lives far away from here, needed for forkchild */
static void closescript(void);
static void
forkchild(struct job *jp, union node *n, int mode)
{
	int oldlvl;

	TRACE(("Child shell %d\n", getpid()));
	oldlvl = shlvl;
	shlvl++;

	closescript();
	clear_traps();
#if JOBS
	/* do job control only in root shell */
	jobctl = 0;
	if (mode != FORK_NOJOB && jp->jobctl && !oldlvl) {
		pid_t pgrp;

		if (jp->nprocs == 0)
			pgrp = getpid();
		else
			pgrp = jp->ps[0].pid;
		/* This can fail because we are doing it in the parent also */
		(void)setpgid(0, pgrp);
		if (mode == FORK_FG)
			xtcsetpgrp(ttyfd, pgrp);
		setsignal(SIGTSTP);
		setsignal(SIGTTOU);
	} else
#endif
	if (mode == FORK_BG) {
		ignoresig(SIGINT);
		ignoresig(SIGQUIT);
		if (jp->nprocs == 0) {
			close(0);
			if (open(bb_dev_null, O_RDONLY) != 0)
				ash_msg_and_raise_error("can't open %s", bb_dev_null);
		}
	}
	if (!oldlvl && iflag) {
		setsignal(SIGINT);
		setsignal(SIGQUIT);
		setsignal(SIGTERM);
	}
	for (jp = curjob; jp; jp = jp->prev_job)
		freejob(jp);
	jobless = 0;
}

static void
forkparent(struct job *jp, union node *n, int mode, pid_t pid)
{
	TRACE(("In parent shell: child = %d\n", pid));
	if (!jp) {
		while (jobless && dowait(DOWAIT_NORMAL, 0) > 0);
		jobless++;
		return;
	}
#if JOBS
	if (mode != FORK_NOJOB && jp->jobctl) {
		int pgrp;

		if (jp->nprocs == 0)
			pgrp = pid;
		else
			pgrp = jp->ps[0].pid;
		/* This can fail because we are doing it in the child also */
		setpgid(pid, pgrp);
	}
#endif
	if (mode == FORK_BG) {
		backgndpid = pid;               /* set $! */
		set_curjob(jp, CUR_RUNNING);
	}
	if (jp) {
		struct procstat *ps = &jp->ps[jp->nprocs++];
		ps->pid = pid;
		ps->status = -1;
		ps->cmd = nullstr;
#if JOBS
		if (jobctl && n)
			ps->cmd = commandtext(n);
#endif
	}
}

static int
forkshell(struct job *jp, union node *n, int mode)
{
	int pid;

	TRACE(("forkshell(%%%d, %p, %d) called\n", jobno(jp), n, mode));
	pid = fork();
	if (pid < 0) {
		TRACE(("Fork failed, errno=%d", errno));
		if (jp)
			freejob(jp);
		ash_msg_and_raise_error("cannot fork");
	}
	if (pid == 0)
		forkchild(jp, n, mode);
	else
		forkparent(jp, n, mode, pid);
	return pid;
}

/*
 * Wait for job to finish.
 *
 * Under job control we have the problem that while a child process is
 * running interrupts generated by the user are sent to the child but not
 * to the shell.  This means that an infinite loop started by an inter-
 * active user may be hard to kill.  With job control turned off, an
 * interactive user may place an interactive program inside a loop.  If
 * the interactive program catches interrupts, the user doesn't want
 * these interrupts to also abort the loop.  The approach we take here
 * is to have the shell ignore interrupt signals while waiting for a
 * foreground process to terminate, and then send itself an interrupt
 * signal if the child process was terminated by an interrupt signal.
 * Unfortunately, some programs want to do a bit of cleanup and then
 * exit on interrupt; unless these processes terminate themselves by
 * sending a signal to themselves (instead of calling exit) they will
 * confuse this approach.
 *
 * Called with interrupts off.
 */
static int
waitforjob(struct job *jp)
{
	int st;

	TRACE(("waitforjob(%%%d) called\n", jobno(jp)));
	while (jp->state == JOBRUNNING) {
		dowait(DOWAIT_BLOCK, jp);
	}
	st = getstatus(jp);
#if JOBS
	if (jp->jobctl) {
		xtcsetpgrp(ttyfd, rootpid);
		/*
		 * This is truly gross.
		 * If we're doing job control, then we did a TIOCSPGRP which
		 * caused us (the shell) to no longer be in the controlling
		 * session -- so we wouldn't have seen any ^C/SIGINT.  So, we
		 * intuit from the subprocess exit status whether a SIGINT
		 * occurred, and if so interrupt ourselves.  Yuck.  - mycroft
		 */
		if (jp->sigint)
			raise(SIGINT);
	}
	if (jp->state == JOBDONE)
#endif
		freejob(jp);
	return st;
}

/*
 * return 1 if there are stopped jobs, otherwise 0
 */
static int
stoppedjobs(void)
{
	struct job *jp;
	int retval;

	retval = 0;
	if (job_warning)
		goto out;
	jp = curjob;
	if (jp && jp->state == JOBSTOPPED) {
		out2str("You have stopped jobs.\n");
		job_warning = 2;
		retval++;
	}
 out:
	return retval;
}


/* ============ redir.c
 *
 * Code for dealing with input/output redirection.
 */

#define EMPTY -2                /* marks an unused slot in redirtab */
#ifndef PIPE_BUF
# define PIPESIZE 4096          /* amount of buffering in a pipe */
#else
# define PIPESIZE PIPE_BUF
#endif

/*
 * Open a file in noclobber mode.
 * The code was copied from bash.
 */
static int
noclobberopen(const char *fname)
{
	int r, fd;
	struct stat finfo, finfo2;

	/*
	 * If the file exists and is a regular file, return an error
	 * immediately.
	 */
	r = stat(fname, &finfo);
	if (r == 0 && S_ISREG(finfo.st_mode)) {
		errno = EEXIST;
		return -1;
	}

	/*
	 * If the file was not present (r != 0), make sure we open it
	 * exclusively so that if it is created before we open it, our open
	 * will fail.  Make sure that we do not truncate an existing file.
	 * Note that we don't turn on O_EXCL unless the stat failed -- if the
	 * file was not a regular file, we leave O_EXCL off.
	 */
	if (r != 0)
		return open(fname, O_WRONLY|O_CREAT|O_EXCL, 0666);
	fd = open(fname, O_WRONLY|O_CREAT, 0666);

	/* If the open failed, return the file descriptor right away. */
	if (fd < 0)
		return fd;

	/*
	 * OK, the open succeeded, but the file may have been changed from a
	 * non-regular file to a regular file between the stat and the open.
	 * We are assuming that the O_EXCL open handles the case where FILENAME
	 * did not exist and is symlinked to an existing file between the stat
	 * and open.
	 */

	/*
	 * If we can open it and fstat the file descriptor, and neither check
	 * revealed that it was a regular file, and the file has not been
	 * replaced, return the file descriptor.
	 */
	if (fstat(fd, &finfo2) == 0 && !S_ISREG(finfo2.st_mode)
	 && finfo.st_dev == finfo2.st_dev && finfo.st_ino == finfo2.st_ino)
		return fd;

	/* The file has been replaced.  badness. */
	close(fd);
	errno = EEXIST;
	return -1;
}

/*
 * Handle here documents.  Normally we fork off a process to write the
 * data to a pipe.  If the document is short, we can stuff the data in
 * the pipe without forking.
 */
/* openhere needs this forward reference */
static void expandhere(union node *arg, int fd);
static int
openhere(union node *redir)
{
	int pip[2];
	size_t len = 0;

	if (pipe(pip) < 0)
		ash_msg_and_raise_error("pipe call failed");
	if (redir->type == NHERE) {
		len = strlen(redir->nhere.doc->narg.text);
		if (len <= PIPESIZE) {
			full_write(pip[1], redir->nhere.doc->narg.text, len);
			goto out;
		}
	}
	if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) {
		close(pip[0]);
		signal(SIGINT, SIG_IGN);
		signal(SIGQUIT, SIG_IGN);
		signal(SIGHUP, SIG_IGN);
#ifdef SIGTSTP
		signal(SIGTSTP, SIG_IGN);
#endif
		signal(SIGPIPE, SIG_DFL);
		if (redir->type == NHERE)
			full_write(pip[1], redir->nhere.doc->narg.text, len);
		else
			expandhere(redir->nhere.doc, pip[1]);
		_exit(0);
	}
 out:
	close(pip[1]);
	return pip[0];
}

static int
openredirect(union node *redir)
{
	char *fname;
	int f;

	switch (redir->nfile.type) {
	case NFROM:
		fname = redir->nfile.expfname;
		f = open(fname, O_RDONLY);
		if (f < 0)
			goto eopen;
		break;
	case NFROMTO:
		fname = redir->nfile.expfname;
		f = open(fname, O_RDWR|O_CREAT|O_TRUNC, 0666);
		if (f < 0)
			goto ecreate;
		break;
	case NTO:
		/* Take care of noclobber mode. */
		if (Cflag) {
			fname = redir->nfile.expfname;
			f = noclobberopen(fname);
			if (f < 0)
				goto ecreate;
			break;
		}
		/* FALLTHROUGH */
	case NCLOBBER:
		fname = redir->nfile.expfname;
		f = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666);
		if (f < 0)
			goto ecreate;
		break;
	case NAPPEND:
		fname = redir->nfile.expfname;
		f = open(fname, O_WRONLY|O_CREAT|O_APPEND, 0666);
		if (f < 0)
			goto ecreate;
		break;
	default:
#if DEBUG
		abort();
#endif
		/* Fall through to eliminate warning. */
	case NTOFD:
	case NFROMFD:
		f = -1;
		break;
	case NHERE:
	case NXHERE:
		f = openhere(redir);
		break;
	}

	return f;
 ecreate:
	ash_msg_and_raise_error("cannot create %s: %s", fname, errmsg(errno, "nonexistent directory"));
 eopen:
	ash_msg_and_raise_error("cannot open %s: %s", fname, errmsg(errno, "no such file"));
}

/*
 * Copy a file descriptor to be >= to.  Returns -1
 * if the source file descriptor is closed, EMPTY if there are no unused
 * file descriptors left.
 */
static int
copyfd(int from, int to)
{
	int newfd;

	newfd = fcntl(from, F_DUPFD, to);
	if (newfd < 0) {
		if (errno == EMFILE)
			return EMPTY;
		ash_msg_and_raise_error("%d: %m", from);
	}
	return newfd;
}

static void
dupredirect(union node *redir, int f)
{
	int fd = redir->nfile.fd;

	if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) {
		if (redir->ndup.dupfd >= 0) {   /* if not ">&-" */
			copyfd(redir->ndup.dupfd, fd);
		}
		return;
	}

	if (f != fd) {
		copyfd(f, fd);
		close(f);
	}
}

/*
 * Process a list of redirection commands.  If the REDIR_PUSH flag is set,
 * old file descriptors are stashed away so that the redirection can be
 * undone by calling popredir.  If the REDIR_BACKQ flag is set, then the
 * standard output, and the standard error if it becomes a duplicate of
 * stdout, is saved in memory.
 */
/* flags passed to redirect */
#define REDIR_PUSH    01        /* save previous values of file descriptors */
#define REDIR_SAVEFD2 03        /* set preverrout */
static void
redirect(union node *redir, int flags)
{
	union node *n;
	struct redirtab *sv;
	int i;
	int fd;
	int newfd;
	int *p;
	nullredirs++;
	if (!redir) {
		return;
	}
	sv = NULL;
	INT_OFF;
	if (flags & REDIR_PUSH) {
		struct redirtab *q;
		q = ckmalloc(sizeof(struct redirtab));
		q->next = redirlist;
		redirlist = q;
		q->nullredirs = nullredirs - 1;
		for (i = 0; i < 10; i++)
			q->renamed[i] = EMPTY;
		nullredirs = 0;
		sv = q;
	}
	n = redir;
	do {
		fd = n->nfile.fd;
		if ((n->nfile.type == NTOFD || n->nfile.type == NFROMFD)
		 && n->ndup.dupfd == fd)
			continue; /* redirect from/to same file descriptor */

		newfd = openredirect(n);
		if (fd == newfd)
			continue;
		if (sv && *(p = &sv->renamed[fd]) == EMPTY) {
			i = fcntl(fd, F_DUPFD, 10);

			if (i == -1) {
				i = errno;
				if (i != EBADF) {
					close(newfd);
					errno = i;
					ash_msg_and_raise_error("%d: %m", fd);
					/* NOTREACHED */
				}
			} else {
				*p = i;
				close(fd);
			}
		} else {
			close(fd);
		}
		dupredirect(n, newfd);
	} while ((n = n->nfile.next));
	INT_ON;
	if (flags & REDIR_SAVEFD2 && sv && sv->renamed[2] >= 0)
		preverrout_fd = sv->renamed[2];
}

/*
 * Undo the effects of the last redirection.
 */
static void
popredir(int drop)
{
	struct redirtab *rp;
	int i;

	if (--nullredirs >= 0)
		return;
	INT_OFF;
	rp = redirlist;
	for (i = 0; i < 10; i++) {
		if (rp->renamed[i] != EMPTY) {
			if (!drop) {
				close(i);
				copyfd(rp->renamed[i], i);
			}
			close(rp->renamed[i]);
		}
	}
	redirlist = rp->next;
	nullredirs = rp->nullredirs;
	free(rp);
	INT_ON;
}

/*
 * Undo all redirections.  Called on error or interrupt.
 */

/*
 * Discard all saved file descriptors.
 */
static void
clearredir(int drop)
{
	for (;;) {
		nullredirs = 0;
		if (!redirlist)
			break;
		popredir(drop);
	}
}

static int
redirectsafe(union node *redir, int flags)
{
	int err;
	volatile int saveint;
	struct jmploc *volatile savehandler = exception_handler;
	struct jmploc jmploc;

	SAVE_INT(saveint);
	err = setjmp(jmploc.loc) * 2;
	if (!err) {
		exception_handler = &jmploc;
		redirect(redir, flags);
	}
	exception_handler = savehandler;
	if (err && exception != EXERROR)
		longjmp(exception_handler->loc, 1);
	RESTORE_INT(saveint);
	return err;
}


/* ============ Routines to expand arguments to commands
 *
 * We have to deal with backquotes, shell variables, and file metacharacters.
 */

/*
 * expandarg flags
 */
#define EXP_FULL        0x1     /* perform word splitting & file globbing */
#define EXP_TILDE       0x2     /* do normal tilde expansion */
#define EXP_VARTILDE    0x4     /* expand tildes in an assignment */
#define EXP_REDIR       0x8     /* file glob for a redirection (1 match only) */
#define EXP_CASE        0x10    /* keeps quotes around for CASE pattern */
#define EXP_RECORD      0x20    /* need to record arguments for ifs breakup */
#define EXP_VARTILDE2   0x40    /* expand tildes after colons only */
#define EXP_WORD        0x80    /* expand word in parameter expansion */
#define EXP_QWORD       0x100   /* expand word in quoted parameter expansion */
/*
 * _rmescape() flags
 */
#define RMESCAPE_ALLOC  0x1     /* Allocate a new string */
#define RMESCAPE_GLOB   0x2     /* Add backslashes for glob */
#define RMESCAPE_QUOTED 0x4     /* Remove CTLESC unless in quotes */
#define RMESCAPE_GROW   0x8     /* Grow strings instead of stalloc */
#define RMESCAPE_HEAP   0x10    /* Malloc strings instead of stalloc */

/*
 * Structure specifying which parts of the string should be searched
 * for IFS characters.
 */
struct ifsregion {
	struct ifsregion *next; /* next region in list */
	int begoff;             /* offset of start of region */
	int endoff;             /* offset of end of region */
	int nulonly;            /* search for nul bytes only */
};

struct arglist {
	struct strlist *list;
	struct strlist **lastp;
};

/* output of current string */
static char *expdest;
/* list of back quote expressions */
static struct nodelist *argbackq;
/* first struct in list of ifs regions */
static struct ifsregion ifsfirst;
/* last struct in list */
static struct ifsregion *ifslastp;
/* holds expanded arg list */
static struct arglist exparg;

/*
 * Our own itoa().
 */
static int
cvtnum(arith_t num)
{
	int len;

	expdest = makestrspace(32, expdest);
#if ENABLE_ASH_MATH_SUPPORT_64
	len = fmtstr(expdest, 32, "%lld", (long long) num);
#else
	len = fmtstr(expdest, 32, "%ld", num);
#endif
	STADJUST(len, expdest);
	return len;
}

static size_t
esclen(const char *start, const char *p)
{
	size_t esc = 0;

	while (p > start && *--p == CTLESC) {
		esc++;
	}
	return esc;
}

/*
 * Remove any CTLESC characters from a string.
 */
static char *
_rmescapes(char *str, int flag)
{
	char *p, *q, *r;
	static const char qchars[] = { CTLESC, CTLQUOTEMARK, 0 };
	unsigned inquotes;
	int notescaped;
	int globbing;

	p = strpbrk(str, qchars);
	if (!p) {
		return str;
	}
	q = p;
	r = str;
	if (flag & RMESCAPE_ALLOC) {
		size_t len = p - str;
		size_t fulllen = len + strlen(p) + 1;

		if (flag & RMESCAPE_GROW) {
			r = makestrspace(fulllen, expdest);
		} else if (flag & RMESCAPE_HEAP) {
			r = ckmalloc(fulllen);
		} else {
			r = stalloc(fulllen);
		}
		q = r;
		if (len > 0) {
			q = memcpy(q, str, len) + len;
		}
	}
	inquotes = (flag & RMESCAPE_QUOTED) ^ RMESCAPE_QUOTED;
	globbing = flag & RMESCAPE_GLOB;
	notescaped = globbing;
	while (*p) {
		if (*p == CTLQUOTEMARK) {
			inquotes = ~inquotes;
			p++;
			notescaped = globbing;
			continue;
		}
		if (*p == '\\') {
			/* naked back slash */
			notescaped = 0;
			goto copy;
		}
		if (*p == CTLESC) {
			p++;
			if (notescaped && inquotes && *p != '/') {
				*q++ = '\\';
			}
		}
		notescaped = globbing;
 copy:
		*q++ = *p++;
	}
	*q = '\0';
	if (flag & RMESCAPE_GROW) {
		expdest = r;
		STADJUST(q - r + 1, expdest);
	}
	return r;
}
#define rmescapes(p) _rmescapes((p), 0)

#define pmatch(a, b) !fnmatch((a), (b), 0)

/*
 * Prepare a pattern for a expmeta (internal glob(3)) call.
 *
 * Returns an stalloced string.
 */
static char *
preglob(const char *pattern, int quoted, int flag)
{
	flag |= RMESCAPE_GLOB;
	if (quoted) {
		flag |= RMESCAPE_QUOTED;
	}
	return _rmescapes((char *)pattern, flag);
}

/*
 * Put a string on the stack.
 */
static void
memtodest(const char *p, size_t len, int syntax, int quotes)
{
	char *q = expdest;

	q = makestrspace(len * 2, q);

	while (len--) {
		int c = signed_char2int(*p++);
		if (!c)
			continue;
		if (quotes && (SIT(c, syntax) == CCTL || SIT(c, syntax) == CBACK))
			USTPUTC(CTLESC, q);
		USTPUTC(c, q);
	}

	expdest = q;
}

static void
strtodest(const char *p, int syntax, int quotes)
{
	memtodest(p, strlen(p), syntax, quotes);
}

/*
 * Record the fact that we have to scan this region of the
 * string for IFS characters.
 */
static void
recordregion(int start, int end, int nulonly)
{
	struct ifsregion *ifsp;

	if (ifslastp == NULL) {
		ifsp = &ifsfirst;
	} else {
		INT_OFF;
		ifsp = ckmalloc(sizeof(*ifsp));
		ifsp->next = NULL;
		ifslastp->next = ifsp;
		INT_ON;
	}
	ifslastp = ifsp;
	ifslastp->begoff = start;
	ifslastp->endoff = end;
	ifslastp->nulonly = nulonly;
}

static void
removerecordregions(int endoff)
{
	if (ifslastp == NULL)
		return;

	if (ifsfirst.endoff > endoff) {
		while (ifsfirst.next != NULL) {
			struct ifsregion *ifsp;
			INT_OFF;
			ifsp = ifsfirst.next->next;
			free(ifsfirst.next);
			ifsfirst.next = ifsp;
			INT_ON;
		}
		if (ifsfirst.begoff > endoff)
			ifslastp = NULL;
		else {
			ifslastp = &ifsfirst;
			ifsfirst.endoff = endoff;
		}
		return;
	}

	ifslastp = &ifsfirst;
	while (ifslastp->next && ifslastp->next->begoff < endoff)
		ifslastp=ifslastp->next;
	while (ifslastp->next != NULL) {
		struct ifsregion *ifsp;
		INT_OFF;
		ifsp = ifslastp->next->next;
		free(ifslastp->next);
		ifslastp->next = ifsp;
		INT_ON;
	}
	if (ifslastp->endoff > endoff)
		ifslastp->endoff = endoff;
}

static char *
exptilde(char *startp, char *p, int flag)
{
	char c;
	char *name;
	struct passwd *pw;
	const char *home;
	int quotes = flag & (EXP_FULL | EXP_CASE);
	int startloc;

	name = p + 1;

	while ((c = *++p) != '\0') {
		switch (c) {
		case CTLESC:
			return startp;
		case CTLQUOTEMARK:
			return startp;
		case ':':
			if (flag & EXP_VARTILDE)
				goto done;
			break;
		case '/':
		case CTLENDVAR:
			goto done;
		}
	}
 done:
	*p = '\0';
	if (*name == '\0') {
		home = lookupvar(homestr);
	} else {
		pw = getpwnam(name);
		if (pw == NULL)
			goto lose;
		home = pw->pw_dir;
	}
	if (!home || !*home)
		goto lose;
	*p = c;
	startloc = expdest - (char *)stackblock();
	strtodest(home, SQSYNTAX, quotes);
	recordregion(startloc, expdest - (char *)stackblock(), 0);
	return p;
 lose:
	*p = c;
	return startp;
}

/*
 * Execute a command inside back quotes.  If it's a builtin command, we
 * want to save its output in a block obtained from malloc.  Otherwise
 * we fork off a subprocess and get the output of the command via a pipe.
 * Should be called with interrupts off.
 */
struct backcmd {                /* result of evalbackcmd */
	int fd;                 /* file descriptor to read from */
	char *buf;              /* buffer */
	int nleft;              /* number of chars in buffer */
	struct job *jp;         /* job structure for command */
};

/* These forward decls are needed to use "eval" code for backticks handling: */
static int back_exitstatus; /* exit status of backquoted command */
#define EV_EXIT 01              /* exit after evaluating tree */
static void evaltree(union node *, int);

static void
evalbackcmd(union node *n, struct backcmd *result)
{
	int saveherefd;

	result->fd = -1;
	result->buf = NULL;
	result->nleft = 0;
	result->jp = NULL;
	if (n == NULL) {
		goto out;
	}

	saveherefd = herefd;
	herefd = -1;

	{
		int pip[2];
		struct job *jp;

		if (pipe(pip) < 0)
			ash_msg_and_raise_error("pipe call failed");
		jp = makejob(n, 1);
		if (forkshell(jp, n, FORK_NOJOB) == 0) {
			FORCE_INT_ON;
			close(pip[0]);
			if (pip[1] != 1) {
				close(1);
				copyfd(pip[1], 1);
				close(pip[1]);
			}
			eflag = 0;
			evaltree(n, EV_EXIT); /* actually evaltreenr... */
			/* NOTREACHED */
		}
		close(pip[1]);
		result->fd = pip[0];
		result->jp = jp;
	}
	herefd = saveherefd;
 out:
	TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
		result->fd, result->buf, result->nleft, result->jp));
}

/*
 * Expand stuff in backwards quotes.
 */
static void
expbackq(union node *cmd, int quoted, int quotes)
{
	struct backcmd in;
	int i;
	char buf[128];
	char *p;
	char *dest;
	int startloc;
	int syntax = quoted? DQSYNTAX : BASESYNTAX;
	struct stackmark smark;

	INT_OFF;
	setstackmark(&smark);
	dest = expdest;
	startloc = dest - (char *)stackblock();
	grabstackstr(dest);
	evalbackcmd(cmd, &in);
	popstackmark(&smark);

	p = in.buf;
	i = in.nleft;
	if (i == 0)
		goto read;
	for (;;) {
		memtodest(p, i, syntax, quotes);
 read:
		if (in.fd < 0)
			break;
		i = safe_read(in.fd, buf, sizeof(buf));
		TRACE(("expbackq: read returns %d\n", i));
		if (i <= 0)
			break;
		p = buf;
	}

	if (in.buf)
		free(in.buf);
	if (in.fd >= 0) {
		close(in.fd);
		back_exitstatus = waitforjob(in.jp);
	}
	INT_ON;

	/* Eat all trailing newlines */
	dest = expdest;
	for (; dest > (char *)stackblock() && dest[-1] == '\n';)
		STUNPUTC(dest);
	expdest = dest;

	if (quoted == 0)
		recordregion(startloc, dest - (char *)stackblock(), 0);
	TRACE(("evalbackq: size=%d: \"%.*s\"\n",
		(dest - (char *)stackblock()) - startloc,
		(dest - (char *)stackblock()) - startloc,
		stackblock() + startloc));
}

#if ENABLE_ASH_MATH_SUPPORT
/*
 * Expand arithmetic expression.  Backup to start of expression,
 * evaluate, place result in (backed up) result, adjust string position.
 */
static void
expari(int quotes)
{
	char *p, *start;
	int begoff;
	int flag;
	int len;

	/*      ifsfree(); */

	/*
	 * This routine is slightly over-complicated for
	 * efficiency.  Next we scan backwards looking for the
	 * start of arithmetic.
	 */
	start = stackblock();
	p = expdest - 1;
	*p = '\0';
	p--;
	do {
		int esc;

		while (*p != CTLARI) {
			p--;
#if DEBUG
			if (p < start) {
				ash_msg_and_raise_error("missing CTLARI (shouldn't happen)");
			}
#endif
		}

		esc = esclen(start, p);
		if (!(esc % 2)) {
			break;
		}

		p -= esc + 1;
	} while (1);

	begoff = p - start;

	removerecordregions(begoff);

	flag = p[1];

	expdest = p;

	if (quotes)
		rmescapes(p + 2);

	len = cvtnum(dash_arith(p + 2));

	if (flag != '"')
		recordregion(begoff, begoff + len, 0);
}
#endif

/* argstr needs it */
static char *evalvar(char *p, int flag);

/*
 * Perform variable and command substitution.  If EXP_FULL is set, output CTLESC
 * characters to allow for further processing.  Otherwise treat
 * $@ like $* since no splitting will be performed.
 */
static void
argstr(char *p, int flag)
{
	static const char spclchars[] = {
		'=',
		':',
		CTLQUOTEMARK,
		CTLENDVAR,
		CTLESC,
		CTLVAR,
		CTLBACKQ,
		CTLBACKQ | CTLQUOTE,
#if ENABLE_ASH_MATH_SUPPORT
		CTLENDARI,
#endif
		0
	};
	const char *reject = spclchars;
	int c;
	int quotes = flag & (EXP_FULL | EXP_CASE);      /* do CTLESC */
	int breakall = flag & EXP_WORD;
	int inquotes;
	size_t length;
	int startloc;

	if (!(flag & EXP_VARTILDE)) {
		reject += 2;
	} else if (flag & EXP_VARTILDE2) {
		reject++;
	}
	inquotes = 0;
	length = 0;
	if (flag & EXP_TILDE) {
		char *q;

		flag &= ~EXP_TILDE;
 tilde:
		q = p;
		if (*q == CTLESC && (flag & EXP_QWORD))
			q++;
		if (*q == '~')
			p = exptilde(p, q, flag);
	}
 start:
	startloc = expdest - (char *)stackblock();
	for (;;) {
		length += strcspn(p + length, reject);
		c = p[length];
		if (c && (!(c & 0x80)
#if ENABLE_ASH_MATH_SUPPORT
					|| c == CTLENDARI
#endif
		   )) {
			/* c == '=' || c == ':' || c == CTLENDARI */
			length++;
		}
		if (length > 0) {
			int newloc;
			expdest = stack_nputstr(p, length, expdest);
			newloc = expdest - (char *)stackblock();
			if (breakall && !inquotes && newloc > startloc) {
				recordregion(startloc, newloc, 0);
			}
			startloc = newloc;
		}
		p += length + 1;
		length = 0;

		switch (c) {
		case '\0':
			goto breakloop;
		case '=':
			if (flag & EXP_VARTILDE2) {
				p--;
				continue;
			}
			flag |= EXP_VARTILDE2;
			reject++;
			/* fall through */
		case ':':
			/*
			 * sort of a hack - expand tildes in variable
			 * assignments (after the first '=' and after ':'s).
			 */
			if (*--p == '~') {
				goto tilde;
			}
			continue;
		}

		switch (c) {
		case CTLENDVAR: /* ??? */
			goto breakloop;
		case CTLQUOTEMARK:
			/* "$@" syntax adherence hack */
			if (
				!inquotes &&
				!memcmp(p, dolatstr, 4) &&
				(p[4] == CTLQUOTEMARK || (
					p[4] == CTLENDVAR &&
					p[5] == CTLQUOTEMARK
				))
			) {
				p = evalvar(p + 1, flag) + 1;
				goto start;
			}
			inquotes = !inquotes;
 addquote:
			if (quotes) {
				p--;
				length++;
				startloc++;
			}
			break;
		case CTLESC:
			startloc++;
			length++;
			goto addquote;
		case CTLVAR:
			p = evalvar(p, flag);
			goto start;
		case CTLBACKQ:
			c = 0;
		case CTLBACKQ|CTLQUOTE:
			expbackq(argbackq->n, c, quotes);
			argbackq = argbackq->next;
			goto start;
#if ENABLE_ASH_MATH_SUPPORT
		case CTLENDARI:
			p--;
			expari(quotes);
			goto start;
#endif
		}
	}
 breakloop:
	;
}

static char *
scanleft(char *startp, char *rmesc, char *rmescend, char *str, int quotes,
	int zero)
{
	char *loc;
	char *loc2;
	char c;

	loc = startp;
	loc2 = rmesc;
	do {
		int match;
		const char *s = loc2;
		c = *loc2;
		if (zero) {
			*loc2 = '\0';
			s = rmesc;
		}
		match = pmatch(str, s);
		*loc2 = c;
		if (match)
			return loc;
		if (quotes && *loc == CTLESC)
			loc++;
		loc++;
		loc2++;
	} while (c);
	return 0;
}

static char *
scanright(char *startp, char *rmesc, char *rmescend, char *str, int quotes,
	int zero)
{
	int esc = 0;
	char *loc;
	char *loc2;

	for (loc = str - 1, loc2 = rmescend; loc >= startp; loc2--) {
		int match;
		char c = *loc2;
		const char *s = loc2;
		if (zero) {
			*loc2 = '\0';
			s = rmesc;
		}
		match = pmatch(str, s);
		*loc2 = c;
		if (match)
			return loc;
		loc--;
		if (quotes) {
			if (--esc < 0) {
				esc = esclen(startp, loc);
			}
			if (esc % 2) {
				esc--;
				loc--;
			}
		}
	}
	return 0;
}

static void varunset(const char *, const char *, const char *, int) ATTRIBUTE_NORETURN;
static void
varunset(const char *end, const char *var, const char *umsg, int varflags)
{
	const char *msg;
	const char *tail;

	tail = nullstr;
	msg = "parameter not set";
	if (umsg) {
		if (*end == CTLENDVAR) {
			if (varflags & VSNUL)
				tail = " or null";
		} else
			msg = umsg;
	}
	ash_msg_and_raise_error("%.*s: %s%s", end - var - 1, var, msg, tail);
}

static const char *
subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags, int quotes)
{
	char *startp;
	char *loc;
	int saveherefd = herefd;
	struct nodelist *saveargbackq = argbackq;
	int amount;
	char *rmesc, *rmescend;
	int zero;
	char *(*scan)(char *, char *, char *, char *, int , int);

	herefd = -1;
	argstr(p, subtype != VSASSIGN && subtype != VSQUESTION ? EXP_CASE : 0);
	STPUTC('\0', expdest);
	herefd = saveherefd;
	argbackq = saveargbackq;
	startp = stackblock() + startloc;

	switch (subtype) {
	case VSASSIGN:
		setvar(str, startp, 0);
		amount = startp - expdest;
		STADJUST(amount, expdest);
		return startp;

	case VSQUESTION:
		varunset(p, str, startp, varflags);
		/* NOTREACHED */
	}

	subtype -= VSTRIMRIGHT;
#if DEBUG
	if (subtype < 0 || subtype > 3)
		abort();
#endif

	rmesc = startp;
	rmescend = stackblock() + strloc;
	if (quotes) {
		rmesc = _rmescapes(startp, RMESCAPE_ALLOC | RMESCAPE_GROW);
		if (rmesc != startp) {
			rmescend = expdest;
			startp = stackblock() + startloc;
		}
	}
	rmescend--;
	str = stackblock() + strloc;
	preglob(str, varflags & VSQUOTE, 0);

	/* zero = subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX */
	zero = subtype >> 1;
	/* VSTRIMLEFT/VSTRIMRIGHTMAX -> scanleft */
	scan = (subtype & 1) ^ zero ? scanleft : scanright;

	loc = scan(startp, rmesc, rmescend, str, quotes, zero);
	if (loc) {
		if (zero) {
			memmove(startp, loc, str - loc);
			loc = startp + (str - loc) - 1;
		}
		*loc = '\0';
		amount = loc - expdest;
		STADJUST(amount, expdest);
	}
	return loc;
}

/*
 * Add the value of a specialized variable to the stack string.
 */
static ssize_t
varvalue(char *name, int varflags, int flags)
{
	int num;
	char *p;
	int i;
	int sep = 0;
	int sepq = 0;
	ssize_t len = 0;
	char **ap;
	int syntax;
	int quoted = varflags & VSQUOTE;
	int subtype = varflags & VSTYPE;
	int quotes = flags & (EXP_FULL | EXP_CASE);

	if (quoted && (flags & EXP_FULL))
		sep = 1 << CHAR_BIT;

	syntax = quoted ? DQSYNTAX : BASESYNTAX;
	switch (*name) {
	case '$':
		num = rootpid;
		goto numvar;
	case '?':
		num = exitstatus;
		goto numvar;
	case '#':
		num = shellparam.nparam;
		goto numvar;
	case '!':
		num = backgndpid;
		if (num == 0)
			return -1;
 numvar:
		len = cvtnum(num);
		break;
	case '-':
		p = makestrspace(NOPTS, expdest);
		for (i = NOPTS - 1; i >= 0; i--) {
			if (optlist[i]) {
				USTPUTC(optletters(i), p);
				len++;
			}
		}
		expdest = p;
		break;
	case '@':
		if (sep)
			goto param;
		/* fall through */
	case '*':
		sep = ifsset() ? signed_char2int(ifsval()[0]) : ' ';
		if (quotes && (SIT(sep, syntax) == CCTL || SIT(sep, syntax) == CBACK))
			sepq = 1;
 param:
		ap = shellparam.p;
		if (!ap)
			return -1;
		while ((p = *ap++)) {
			size_t partlen;

			partlen = strlen(p);
			len += partlen;

			if (!(subtype == VSPLUS || subtype == VSLENGTH))
				memtodest(p, partlen, syntax, quotes);

			if (*ap && sep) {
				char *q;

				len++;
				if (subtype == VSPLUS || subtype == VSLENGTH) {
					continue;
				}
				q = expdest;
				if (sepq)
					STPUTC(CTLESC, q);
				STPUTC(sep, q);
				expdest = q;
			}
		}
		return len;
	case '0':
	case '1':
	case '2':
	case '3':
	case '4':
	case '5':
	case '6':
	case '7':
	case '8':
	case '9':
		num = atoi(name);
		if (num < 0 || num > shellparam.nparam)
			return -1;
		p = num ? shellparam.p[num - 1] : arg0;
		goto value;
	default:
		p = lookupvar(name);
 value:
		if (!p)
			return -1;

		len = strlen(p);
		if (!(subtype == VSPLUS || subtype == VSLENGTH))
			memtodest(p, len, syntax, quotes);
		return len;
	}

	if (subtype == VSPLUS || subtype == VSLENGTH)
		STADJUST(-len, expdest);
	return len;
}

/*
 * Expand a variable, and return a pointer to the next character in the
 * input string.
 */
static char *
evalvar(char *p, int flag)
{
	int subtype;
	int varflags;
	char *var;
	int patloc;
	int c;
	int startloc;
	ssize_t varlen;
	int easy;
	int quotes;
	int quoted;

	quotes = flag & (EXP_FULL | EXP_CASE);
	varflags = *p++;
	subtype = varflags & VSTYPE;
	quoted = varflags & VSQUOTE;
	var = p;
	easy = (!quoted || (*var == '@' && shellparam.nparam));
	startloc = expdest - (char *)stackblock();
	p = strchr(p, '=') + 1;

 again:
	varlen = varvalue(var, varflags, flag);
	if (varflags & VSNUL)
		varlen--;

	if (subtype == VSPLUS) {
		varlen = -1 - varlen;
		goto vsplus;
	}

	if (subtype == VSMINUS) {
 vsplus:
		if (varlen < 0) {
			argstr(
				p, flag | EXP_TILDE |
					(quoted ?  EXP_QWORD : EXP_WORD)
			);
			goto end;
		}
		if (easy)
			goto record;
		goto end;
	}

	if (subtype == VSASSIGN || subtype == VSQUESTION) {
		if (varlen < 0) {
			if (subevalvar(p, var, 0, subtype, startloc, varflags, 0)) {
				varflags &= ~VSNUL;
				/*
				 * Remove any recorded regions beyond
				 * start of variable
				 */
				removerecordregions(startloc);
				goto again;
			}
			goto end;
		}
		if (easy)
			goto record;
		goto end;
	}

	if (varlen < 0 && uflag)
		varunset(p, var, 0, 0);

	if (subtype == VSLENGTH) {
		cvtnum(varlen > 0 ? varlen : 0);
		goto record;
	}

	if (subtype == VSNORMAL) {
		if (!easy)
			goto end;
 record:
		recordregion(startloc, expdest - (char *)stackblock(), quoted);
		goto end;
	}

#if DEBUG
	switch (subtype) {
	case VSTRIMLEFT:
	case VSTRIMLEFTMAX:
	case VSTRIMRIGHT:
	case VSTRIMRIGHTMAX:
		break;
	default:
		abort();
	}
#endif

	if (varlen >= 0) {
		/*
		 * Terminate the string and start recording the pattern
		 * right after it
		 */
		STPUTC('\0', expdest);
		patloc = expdest - (char *)stackblock();
		if (subevalvar(p, NULL, patloc, subtype,
				startloc, varflags, quotes) == 0) {
			int amount = expdest - (
				(char *)stackblock() + patloc - 1
			);
			STADJUST(-amount, expdest);
		}
		/* Remove any recorded regions beyond start of variable */
		removerecordregions(startloc);
		goto record;
	}

 end:
	if (subtype != VSNORMAL) {      /* skip to end of alternative */
		int nesting = 1;
		for (;;) {
			c = *p++;
			if (c == CTLESC)
				p++;
			else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
				if (varlen >= 0)
					argbackq = argbackq->next;
			} else if (c == CTLVAR) {
				if ((*p++ & VSTYPE) != VSNORMAL)
					nesting++;
			} else if (c == CTLENDVAR) {
				if (--nesting == 0)
					break;
			}
		}
	}
	return p;
}

/*
 * Break the argument string into pieces based upon IFS and add the
 * strings to the argument list.  The regions of the string to be
 * searched for IFS characters have been stored by recordregion.
 */
static void
ifsbreakup(char *string, struct arglist *arglist)
{
	struct ifsregion *ifsp;
	struct strlist *sp;
	char *start;
	char *p;
	char *q;
	const char *ifs, *realifs;
	int ifsspc;
	int nulonly;

	start = string;
	if (ifslastp != NULL) {
		ifsspc = 0;
		nulonly = 0;
		realifs = ifsset() ? ifsval() : defifs;
		ifsp = &ifsfirst;
		do {
			p = string + ifsp->begoff;
			nulonly = ifsp->nulonly;
			ifs = nulonly ? nullstr : realifs;
			ifsspc = 0;
			while (p < string + ifsp->endoff) {
				q = p;
				if (*p == CTLESC)
					p++;
				if (!strchr(ifs, *p)) {
					p++;
					continue;
				}
				if (!nulonly)
					ifsspc = (strchr(defifs, *p) != NULL);
				/* Ignore IFS whitespace at start */
				if (q == start && ifsspc) {
					p++;
					start = p;
					continue;
				}
				*q = '\0';
				sp = stalloc(sizeof(*sp));
				sp->text = start;
				*arglist->lastp = sp;
				arglist->lastp = &sp->next;
				p++;
				if (!nulonly) {
					for (;;) {
						if (p >= string + ifsp->endoff) {
							break;
						}
						q = p;
						if (*p == CTLESC)
							p++;
						if (strchr(ifs, *p) == NULL ) {
							p = q;
							break;
						} else if (strchr(defifs, *p) == NULL) {
							if (ifsspc) {
								p++;
								ifsspc = 0;
							} else {
								p = q;
								break;
							}
						} else
							p++;
					}
				}
				start = p;
			} /* while */
			ifsp = ifsp->next;
		} while (ifsp != NULL);
		if (nulonly)
			goto add;
	}

	if (!*start)
		return;

 add:
	sp = stalloc(sizeof(*sp));
	sp->text = start;
	*arglist->lastp = sp;
	arglist->lastp = &sp->next;
}

static void
ifsfree(void)
{
	struct ifsregion *p;

	INT_OFF;
	p = ifsfirst.next;
	do {
		struct ifsregion *ifsp;
		ifsp = p->next;
		free(p);
		p = ifsp;
	} while (p);
	ifslastp = NULL;
	ifsfirst.next = NULL;
	INT_ON;
}

/*
 * Add a file name to the list.
 */
static void
addfname(const char *name)
{
	struct strlist *sp;

	sp = stalloc(sizeof(*sp));
	sp->text = ststrdup(name);
	*exparg.lastp = sp;
	exparg.lastp = &sp->next;
}

static char *expdir;

/*
 * Do metacharacter (i.e. *, ?, [...]) expansion.
 */
static void
expmeta(char *enddir, char *name)
{
	char *p;
	const char *cp;
	char *start;
	char *endname;
	int metaflag;
	struct stat statb;
	DIR *dirp;
	struct dirent *dp;
	int atend;
	int matchdot;

	metaflag = 0;
	start = name;
	for (p = name; *p; p++) {
		if (*p == '*' || *p == '?')
			metaflag = 1;
		else if (*p == '[') {
			char *q = p + 1;
			if (*q == '!')
				q++;
			for (;;) {
				if (*q == '\\')
					q++;
				if (*q == '/' || *q == '\0')
					break;
				if (*++q == ']') {
					metaflag = 1;
					break;
				}
			}
		} else if (*p == '\\')
			p++;
		else if (*p == '/') {
			if (metaflag)
				goto out;
			start = p + 1;
		}
	}
 out:
	if (metaflag == 0) {    /* we've reached the end of the file name */
		if (enddir != expdir)
			metaflag++;
		p = name;
		do {
			if (*p == '\\')
				p++;
			*enddir++ = *p;
		} while (*p++);
		if (metaflag == 0 || lstat(expdir, &statb) >= 0)
			addfname(expdir);
		return;
	}
	endname = p;
	if (name < start) {
		p = name;
		do {
			if (*p == '\\')
				p++;
			*enddir++ = *p++;
		} while (p < start);
	}
	if (enddir == expdir) {
		cp = ".";
	} else if (enddir == expdir + 1 && *expdir == '/') {
		cp = "/";
	} else {
		cp = expdir;
		enddir[-1] = '\0';
	}
	dirp = opendir(cp);
	if (dirp == NULL)
		return;
	if (enddir != expdir)
		enddir[-1] = '/';
	if (*endname == 0) {
		atend = 1;
	} else {
		atend = 0;
		*endname++ = '\0';
	}
	matchdot = 0;
	p = start;
	if (*p == '\\')
		p++;
	if (*p == '.')
		matchdot++;
	while (! intpending && (dp = readdir(dirp)) != NULL) {
		if (dp->d_name[0] == '.' && ! matchdot)
			continue;
		if (pmatch(start, dp->d_name)) {
			if (atend) {
				strcpy(enddir, dp->d_name);
				addfname(expdir);
			} else {
				for (p = enddir, cp = dp->d_name; (*p++ = *cp++) != '\0';)
					continue;
				p[-1] = '/';
				expmeta(p, endname);
			}
		}
	}
	closedir(dirp);
	if (! atend)
		endname[-1] = '/';
}

static struct strlist *
msort(struct strlist *list, int len)
{
	struct strlist *p, *q = NULL;
	struct strlist **lpp;
	int half;
	int n;

	if (len <= 1)
		return list;
	half = len >> 1;
	p = list;
	for (n = half; --n >= 0; ) {
		q = p;
		p = p->next;
	}
	q->next = NULL;                 /* terminate first half of list */
	q = msort(list, half);          /* sort first half of list */
	p = msort(p, len - half);               /* sort second half */
	lpp = &list;
	for (;;) {
#if ENABLE_LOCALE_SUPPORT
		if (strcoll(p->text, q->text) < 0)
#else
		if (strcmp(p->text, q->text) < 0)
#endif
						{
			*lpp = p;
			lpp = &p->next;
			p = *lpp;
			if (p == NULL) {
				*lpp = q;
				break;
			}
		} else {
			*lpp = q;
			lpp = &q->next;
			q = *lpp;
			if (q == NULL) {
				*lpp = p;
				break;
			}
		}
	}
	return list;
}

/*
 * Sort the results of file name expansion.  It calculates the number of
 * strings to sort and then calls msort (short for merge sort) to do the
 * work.
 */
static struct strlist *
expsort(struct strlist *str)
{
	int len;
	struct strlist *sp;

	len = 0;
	for (sp = str; sp; sp = sp->next)
		len++;
	return msort(str, len);
}

static void
expandmeta(struct strlist *str, int flag)
{
	static const char metachars[] = {
		'*', '?', '[', 0
	};
	/* TODO - EXP_REDIR */

	while (str) {
		struct strlist **savelastp;
		struct strlist *sp;
		char *p;

		if (fflag)
			goto nometa;
		if (!strpbrk(str->text, metachars))
			goto nometa;
		savelastp = exparg.lastp;

		INT_OFF;
		p = preglob(str->text, 0, RMESCAPE_ALLOC | RMESCAPE_HEAP);
		{
			int i = strlen(str->text);
			expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
		}

		expmeta(expdir, p);
		free(expdir);
		if (p != str->text)
			free(p);
		INT_ON;
		if (exparg.lastp == savelastp) {
			/*
			 * no matches
			 */
 nometa:
			*exparg.lastp = str;
			rmescapes(str->text);
			exparg.lastp = &str->next;
		} else {
			*exparg.lastp = NULL;
			*savelastp = sp = expsort(*savelastp);
			while (sp->next != NULL)
				sp = sp->next;
			exparg.lastp = &sp->next;
		}
		str = str->next;
	}
}

/*
 * Perform variable substitution and command substitution on an argument,
 * placing the resulting list of arguments in arglist.  If EXP_FULL is true,
 * perform splitting and file name expansion.  When arglist is NULL, perform
 * here document expansion.
 */
static void
expandarg(union node *arg, struct arglist *arglist, int flag)
{
	struct strlist *sp;
	char *p;

	argbackq = arg->narg.backquote;
	STARTSTACKSTR(expdest);
	ifsfirst.next = NULL;
	ifslastp = NULL;
	argstr(arg->narg.text, flag);
	p = _STPUTC('\0', expdest);
	expdest = p - 1;
	if (arglist == NULL) {
		return;                 /* here document expanded */
	}
	p = grabstackstr(p);
	exparg.lastp = &exparg.list;
	/*
	 * TODO - EXP_REDIR
	 */
	if (flag & EXP_FULL) {
		ifsbreakup(p, &exparg);
		*exparg.lastp = NULL;
		exparg.lastp = &exparg.list;
		expandmeta(exparg.list, flag);
	} else {
		if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
			rmescapes(p);
		sp = stalloc(sizeof(*sp));
		sp->text = p;
		*exparg.lastp = sp;
		exparg.lastp = &sp->next;
	}
	if (ifsfirst.next)
		ifsfree();
	*exparg.lastp = NULL;
	if (exparg.list) {
		*arglist->lastp = exparg.list;
		arglist->lastp = exparg.lastp;
	}
}

/*
 * Expand shell variables and backquotes inside a here document.
 */
static void
expandhere(union node *arg, int fd)
{
	herefd = fd;
	expandarg(arg, (struct arglist *)NULL, 0);
	full_write(fd, stackblock(), expdest - (char *)stackblock());
}

/*
 * Returns true if the pattern matches the string.
 */
static int
patmatch(char *pattern, const char *string)
{
	return pmatch(preglob(pattern, 0, 0), string);
}

/*
 * See if a pattern matches in a case statement.
 */
static int
casematch(union node *pattern, char *val)
{
	struct stackmark smark;
	int result;

	setstackmark(&smark);
	argbackq = pattern->narg.backquote;
	STARTSTACKSTR(expdest);
	ifslastp = NULL;
	argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
	STACKSTRNUL(expdest);
	result = patmatch(stackblock(), val);
	popstackmark(&smark);
	return result;
}


/* ============ find_command */

#if ENABLE_FEATURE_SH_STANDALONE_SHELL
static int
is_safe_applet(char *name)
{
	/* It isn't a bug to have non-existent applet here... */
	/* ...just a waste of space... */
	static const char safe_applets[][8] = {
		"["
		USE_AWK    (, "awk"    )
		USE_CAT    (, "cat"    )
		USE_CHMOD  (, "chmod"  )
		USE_CHOWN  (, "chown"  )
		USE_CP     (, "cp"     )
		USE_CUT    (, "cut"    )
		USE_DD     (, "dd"     )
		USE_ECHO   (, "echo"   )
		USE_FIND   (, "find"   )
		USE_HEXDUMP(, "hexdump")
		USE_LN     (, "ln"     )
		USE_LS     (, "ls"     )
		USE_MKDIR  (, "mkdir"  )
		USE_RM     (, "rm"     )
		USE_SORT   (, "sort"   )
		USE_TEST   (, "test"   )
		USE_TOUCH  (, "touch"  )
		USE_XARGS  (, "xargs"  )
	};
	int n = sizeof(safe_applets) / sizeof(safe_applets[0]);
	int i;
	for (i = 0; i < n; i++)
		if (strcmp(safe_applets[i], name) == 0)
			return 1;

	return 0;
}
#endif

struct builtincmd {
	const char *name;
	int (*builtin)(int, char **);
	/* unsigned flags; */
};
#define IS_BUILTIN_SPECIAL(b) ((b)->name[0] & 1)
#define IS_BUILTIN_REGULAR(b) ((b)->name[0] & 2)
#define IS_BUILTIN_ASSIGN(b) ((b)->name[0] & 4)

struct cmdentry {
	int cmdtype;
	union param {
		int index;
		const struct builtincmd *cmd;
		struct funcnode *func;
	} u;
};
/* values of cmdtype */
#define CMDUNKNOWN      -1      /* no entry in table for command */
#define CMDNORMAL       0       /* command is an executable program */
#define CMDFUNCTION     1       /* command is a shell function */
#define CMDBUILTIN      2       /* command is a shell builtin */

/* action to find_command() */
#define DO_ERR          0x01    /* prints errors */
#define DO_ABS          0x02    /* checks absolute paths */
#define DO_NOFUNC       0x04    /* don't return shell functions, for command */
#define DO_ALTPATH      0x08    /* using alternate path */
#define DO_ALTBLTIN     0x20    /* %builtin in alt. path */

static void find_command(char *, struct cmdentry *, int, const char *);


/* ============ Hashing commands */

/*
 * When commands are first encountered, they are entered in a hash table.
 * This ensures that a full path search will not have to be done for them
 * on each invocation.
 *
 * We should investigate converting to a linear search, even though that
 * would make the command name "hash" a misnomer.
 */

#define CMDTABLESIZE 31         /* should be prime */
#define ARB 1                   /* actual size determined at run time */

struct tblentry {
	struct tblentry *next;  /* next entry in hash chain */
	union param param;      /* definition of builtin function */
	short cmdtype;          /* index identifying command */
	char rehash;            /* if set, cd done since entry created */
	char cmdname[ARB];      /* name of command */
};

static struct tblentry *cmdtable[CMDTABLESIZE];
static int builtinloc = -1;             /* index in path of %builtin, or -1 */

static void
tryexec(char *cmd, char **argv, char **envp)
{
	int repeated = 0;

#if ENABLE_FEATURE_SH_STANDALONE_SHELL
	if (strchr(cmd, '/') == NULL) {
		struct BB_applet *a;
		char **c;

		a = find_applet_by_name(cmd);
		if (a) {
			if (is_safe_applet(cmd)) {
				c = argv;
				while (*c)
					c++;
				applet_name = cmd;
				exit(a->main(c - argv, argv));
			}
			/* re-exec ourselves with the new arguments */
			execve(CONFIG_BUSYBOX_EXEC_PATH, argv, envp);
			/* If they called chroot or otherwise made the binary no longer
			 * executable, fall through */
		}
	}
#endif

 repeat:
#ifdef SYSV
	do {
		execve(cmd, argv, envp);
	} while (errno == EINTR);
#else
	execve(cmd, argv, envp);
#endif
	if (repeated++) {
		free(argv);
	} else if (errno == ENOEXEC) {
		char **ap;
		char **new;

		for (ap = argv; *ap; ap++)
			;
		ap = new = ckmalloc((ap - argv + 2) * sizeof(char *));
		ap[1] = cmd;
		*ap = cmd = (char *)DEFAULT_SHELL;
		ap += 2;
		argv++;
		while ((*ap++ = *argv++))
			;
		argv = new;
		goto repeat;
	}
}

/*
 * Exec a program.  Never returns.  If you change this routine, you may
 * have to change the find_command routine as well.
 */
#define environment() listvars(VEXPORT, VUNSET, 0)
static void shellexec(char **, const char *, int) ATTRIBUTE_NORETURN;
static void
shellexec(char **argv, const char *path, int idx)
{
	char *cmdname;
	int e;
	char **envp;
	int exerrno;

	clearredir(1);
	envp = environment();
	if (strchr(argv[0], '/')
#if ENABLE_FEATURE_SH_STANDALONE_SHELL
	 || find_applet_by_name(argv[0])
#endif
	) {
		tryexec(argv[0], argv, envp);
		e = errno;
	} else {
		e = ENOENT;
		while ((cmdname = padvance(&path, argv[0])) != NULL) {
			if (--idx < 0 && pathopt == NULL) {
				tryexec(cmdname, argv, envp);
				if (errno != ENOENT && errno != ENOTDIR)
					e = errno;
			}
			stunalloc(cmdname);
		}
	}

	/* Map to POSIX errors */
	switch (e) {
	case EACCES:
		exerrno = 126;
		break;
	case ENOENT:
		exerrno = 127;
		break;
	default:
		exerrno = 2;
		break;
	}
	exitstatus = exerrno;
	TRACE(("shellexec failed for %s, errno %d, suppressint %d\n",
		argv[0], e, suppressint ));
	ash_msg_and_raise(EXEXEC, "%s: %s", argv[0], errmsg(e, "not found"));
	/* NOTREACHED */
}

static void
printentry(struct tblentry *cmdp)
{
	int idx;
	const char *path;
	char *name;

	idx = cmdp->param.index;
	path = pathval();
	do {
		name = padvance(&path, cmdp->cmdname);
		stunalloc(name);
	} while (--idx >= 0);
	out1fmt("%s%s\n", name, (cmdp->rehash ? "*" : nullstr));
}

/*
 * Clear out command entries.  The argument specifies the first entry in
 * PATH which has changed.
 */
static void
clearcmdentry(int firstchange)
{
	struct tblentry **tblp;
	struct tblentry **pp;
	struct tblentry *cmdp;

	INT_OFF;
	for (tblp = cmdtable; tblp < &cmdtable[CMDTABLESIZE]; tblp++) {
		pp = tblp;
		while ((cmdp = *pp) != NULL) {
			if ((cmdp->cmdtype == CMDNORMAL &&
			     cmdp->param.index >= firstchange)
			 || (cmdp->cmdtype == CMDBUILTIN &&
			     builtinloc >= firstchange)
			) {
				*pp = cmdp->next;
				free(cmdp);
			} else {
				pp = &cmdp->next;
			}
		}
	}
	INT_ON;
}

/*
 * Locate a command in the command hash table.  If "add" is nonzero,
 * add the command to the table if it is not already present.  The
 * variable "lastcmdentry" is set to point to the address of the link
 * pointing to the entry, so that delete_cmd_entry can delete the
 * entry.
 *
 * Interrupts must be off if called with add != 0.
 */
static struct tblentry **lastcmdentry;

static struct tblentry *
cmdlookup(const char *name, int add)
{
	unsigned int hashval;
	const char *p;
	struct tblentry *cmdp;
	struct tblentry **pp;

	p = name;
	hashval = (unsigned char)*p << 4;
	while (*p)
		hashval += (unsigned char)*p++;
	hashval &= 0x7FFF;
	pp = &cmdtable[hashval % CMDTABLESIZE];
	for (cmdp = *pp; cmdp; cmdp = cmdp->next) {
		if (strcmp(cmdp->cmdname, name) == 0)
			break;
		pp = &cmdp->next;
	}
	if (add && cmdp == NULL) {
		cmdp = *pp = ckmalloc(sizeof(struct tblentry) - ARB
					+ strlen(name) + 1);
		cmdp->next = NULL;
		cmdp->cmdtype = CMDUNKNOWN;
		strcpy(cmdp->cmdname, name);
	}
	lastcmdentry = pp;
	return cmdp;
}

/*
 * Delete the command entry returned on the last lookup.
 */
static void
delete_cmd_entry(void)
{
	struct tblentry *cmdp;

	INT_OFF;
	cmdp = *lastcmdentry;
	*lastcmdentry = cmdp->next;
	if (cmdp->cmdtype == CMDFUNCTION)
		freefunc(cmdp->param.func);
	free(cmdp);
	INT_ON;
}

/*
 * Add a new command entry, replacing any existing command entry for
 * the same name - except special builtins.
 */
static void
addcmdentry(char *name, struct cmdentry *entry)
{
	struct tblentry *cmdp;

	cmdp = cmdlookup(name, 1);
	if (cmdp->cmdtype == CMDFUNCTION) {
		freefunc(cmdp->param.func);
	}
	cmdp->cmdtype = entry->cmdtype;
	cmdp->param = entry->u;
	cmdp->rehash = 0;
}

static int
hashcmd(int argc, char **argv)
{
	struct tblentry **pp;
	struct tblentry *cmdp;
	int c;
	struct cmdentry entry;
	char *name;

	while ((c = nextopt("r")) != '\0') {
		clearcmdentry(0);
		return 0;
	}
	if (*argptr == NULL) {
		for (pp = cmdtable; pp < &cmdtable[CMDTABLESIZE]; pp++) {
			for (cmdp = *pp; cmdp; cmdp = cmdp->next) {
				if (cmdp->cmdtype == CMDNORMAL)
					printentry(cmdp);
			}
		}
		return 0;
	}
	c = 0;
	while ((name = *argptr) != NULL) {
		cmdp = cmdlookup(name, 0);
		if (cmdp != NULL
		 && (cmdp->cmdtype == CMDNORMAL
		     || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)))
			delete_cmd_entry();
		find_command(name, &entry, DO_ERR, pathval());
		if (entry.cmdtype == CMDUNKNOWN)
			c = 1;
		argptr++;
	}
	return c;
}

/*
 * Called when a cd is done.  Marks all commands so the next time they
 * are executed they will be rehashed.
 */
static void
hashcd(void)
{
	struct tblentry **pp;
	struct tblentry *cmdp;

	for (pp = cmdtable; pp < &cmdtable[CMDTABLESIZE]; pp++) {
		for (cmdp = *pp; cmdp; cmdp = cmdp->next) {
			if (cmdp->cmdtype == CMDNORMAL || (
				cmdp->cmdtype == CMDBUILTIN &&
				!(IS_BUILTIN_REGULAR(cmdp->param.cmd)) &&
				builtinloc > 0
			))
				cmdp->rehash = 1;
		}
	}
}

/*
 * Fix command hash table when PATH changed.
 * Called before PATH is changed.  The argument is the new value of PATH;
 * pathval() still returns the old value at this point.
 * Called with interrupts off.
 */
static void
changepath(const char *newval)
{
	const char *old, *new;
	int idx;
	int firstchange;
	int idx_bltin;

	old = pathval();
	new = newval;
	firstchange = 9999;     /* assume no change */
	idx = 0;
	idx_bltin = -1;
	for (;;) {
		if (*old != *new) {
			firstchange = idx;
			if ((*old == '\0' && *new == ':')
			 || (*old == ':' && *new == '\0'))
				firstchange++;
			old = new;      /* ignore subsequent differences */
		}
		if (*new == '\0')
			break;
		if (*new == '%' && idx_bltin < 0 && prefix(new + 1, "builtin"))
			idx_bltin = idx;
		if (*new == ':') {
			idx++;
		}
		new++, old++;
	}
	if (builtinloc < 0 && idx_bltin >= 0)
		builtinloc = idx_bltin;             /* zap builtins */
	if (builtinloc >= 0 && idx_bltin < 0)
		firstchange = 0;
	clearcmdentry(firstchange);
	builtinloc = idx_bltin;
}

#define TEOF 0
#define TNL 1
#define TREDIR 2
#define TWORD 3
#define TSEMI 4
#define TBACKGND 5
#define TAND 6
#define TOR 7
#define TPIPE 8
#define TLP 9
#define TRP 10
#define TENDCASE 11
#define TENDBQUOTE 12
#define TNOT 13
#define TCASE 14
#define TDO 15
#define TDONE 16
#define TELIF 17
#define TELSE 18
#define TESAC 19
#define TFI 20
#define TFOR 21
#define TIF 22
#define TIN 23
#define TTHEN 24
#define TUNTIL 25
#define TWHILE 26
#define TBEGIN 27
#define TEND 28

/* first char is indicating which tokens mark the end of a list */
static const char *const tokname_array[] = {
	"\1end of file",
	"\0newline",
	"\0redirection",
	"\0word",
	"\0;",
	"\0&",
	"\0&&",
	"\0||",
	"\0|",
	"\0(",
	"\1)",
	"\1;;",
	"\1`",
#define KWDOFFSET 13
	/* the following are keywords */
	"\0!",
	"\0case",
	"\1do",
	"\1done",
	"\1elif",
	"\1else",
	"\1esac",
	"\1fi",
	"\0for",
	"\0if",
	"\0in",
	"\1then",
	"\0until",
	"\0while",
	"\0{",
	"\1}",
};

static const char *
tokname(int tok)
{
	static char buf[16];

	if (tok >= TSEMI)
		buf[0] = '"';
	sprintf(buf + (tok >= TSEMI), "%s%c",
			tokname_array[tok] + 1, (tok >= TSEMI ? '"' : 0));
	return buf;
}

/* Wrapper around strcmp for qsort/bsearch/... */
static int
pstrcmp(const void *a, const void *b)
{
	return strcmp((const char *) a, (*(const char *const *) b) + 1);
}

static const char *const *
findkwd(const char *s)
{
	return bsearch(s, tokname_array + KWDOFFSET,
			(sizeof(tokname_array) / sizeof(const char *)) - KWDOFFSET,
			sizeof(const char *), pstrcmp);
}

/*
 * Locate and print what a word is...
 */
#if ENABLE_ASH_CMDCMD
static int
describe_command(char *command, int describe_command_verbose)
#else
#define describe_command_verbose 1
static int
describe_command(char *command)
#endif
{
	struct cmdentry entry;
	struct tblentry *cmdp;
#if ENABLE_ASH_ALIAS
	const struct alias *ap;
#endif
	const char *path = pathval();

	if (describe_command_verbose) {
		out1str(command);
	}

	/* First look at the keywords */
	if (findkwd(command)) {
		out1str(describe_command_verbose ? " is a shell keyword" : command);
		goto out;
	}

#if ENABLE_ASH_ALIAS
	/* Then look at the aliases */
	ap = lookupalias(command, 0);
	if (ap != NULL) {
		if (describe_command_verbose) {
			out1fmt(" is an alias for %s", ap->val);
		} else {
			out1str("alias ");
			printalias(ap);
			return 0;
		}
		goto out;
	}
#endif
	/* Then check if it is a tracked alias */
	cmdp = cmdlookup(command, 0);
	if (cmdp != NULL) {
		entry.cmdtype = cmdp->cmdtype;
		entry.u = cmdp->param;
	} else {
		/* Finally use brute force */
		find_command(command, &entry, DO_ABS, path);
	}

	switch (entry.cmdtype) {
	case CMDNORMAL: {
		int j = entry.u.index;
		char *p;
		if (j == -1) {
			p = command;
		} else {
			do {
				p = padvance(&path, command);
				stunalloc(p);
			} while (--j >= 0);
		}
		if (describe_command_verbose) {
			out1fmt(" is%s %s",
				(cmdp ? " a tracked alias for" : nullstr), p
			);
		} else {
			out1str(p);
		}
		break;
	}

	case CMDFUNCTION:
		if (describe_command_verbose) {
			out1str(" is a shell function");
		} else {
			out1str(command);
		}
		break;

	case CMDBUILTIN:
		if (describe_command_verbose) {
			out1fmt(" is a %sshell builtin",
				IS_BUILTIN_SPECIAL(entry.u.cmd) ?
					"special " : nullstr
			);
		} else {
			out1str(command);
		}
		break;

	default:
		if (describe_command_verbose) {
			out1str(": not found\n");
		}
		return 127;
	}
 out:
	outstr("\n", stdout);
	return 0;
}

static int
typecmd(int argc, char **argv)
{
	int i;
	int err = 0;

	for (i = 1; i < argc; i++) {
#if ENABLE_ASH_CMDCMD
		err |= describe_command(argv[i], 1);
#else
		err |= describe_command(argv[i]);
#endif
	}
	return err;
}

#if ENABLE_ASH_CMDCMD
static int
commandcmd(int argc, char **argv)
{
	int c;
	enum {
		VERIFY_BRIEF = 1,
		VERIFY_VERBOSE = 2,
	} verify = 0;

	while ((c = nextopt("pvV")) != '\0')
		if (c == 'V')
			verify |= VERIFY_VERBOSE;
		else if (c == 'v')
			verify |= VERIFY_BRIEF;
#if DEBUG
		else if (c != 'p')
			abort();
#endif
	if (verify)
		return describe_command(*argptr, verify - VERIFY_BRIEF);

	return 0;
}
#endif


/* ============ eval.c */

static int funcblocksize;          /* size of structures in function */
static int funcstringsize;         /* size of strings in node */
static void *funcblock;            /* block to allocate function from */
static char *funcstring;           /* block to allocate strings from */

/* flags in argument to evaltree */
#define EV_EXIT 01              /* exit after evaluating tree */
#define EV_TESTED 02            /* exit status is checked; ignore -e flag */
#define EV_BACKCMD 04           /* command executing within back quotes */

static const short nodesize[26] = {
	SHELL_ALIGN(sizeof(struct ncmd)),
	SHELL_ALIGN(sizeof(struct npipe)),
	SHELL_ALIGN(sizeof(struct nredir)),
	SHELL_ALIGN(sizeof(struct nredir)),
	SHELL_ALIGN(sizeof(struct nredir)),
	SHELL_ALIGN(sizeof(struct nbinary)),
	SHELL_ALIGN(sizeof(struct nbinary)),
	SHELL_ALIGN(sizeof(struct nbinary)),
	SHELL_ALIGN(sizeof(struct nif)),
	SHELL_ALIGN(sizeof(struct nbinary)),
	SHELL_ALIGN(sizeof(struct nbinary)),
	SHELL_ALIGN(sizeof(struct nfor)),
	SHELL_ALIGN(sizeof(struct ncase)),
	SHELL_ALIGN(sizeof(struct nclist)),
	SHELL_ALIGN(sizeof(struct narg)),
	SHELL_ALIGN(sizeof(struct narg)),
	SHELL_ALIGN(sizeof(struct nfile)),
	SHELL_ALIGN(sizeof(struct nfile)),
	SHELL_ALIGN(sizeof(struct nfile)),
	SHELL_ALIGN(sizeof(struct nfile)),
	SHELL_ALIGN(sizeof(struct nfile)),
	SHELL_ALIGN(sizeof(struct ndup)),
	SHELL_ALIGN(sizeof(struct ndup)),
	SHELL_ALIGN(sizeof(struct nhere)),
	SHELL_ALIGN(sizeof(struct nhere)),
	SHELL_ALIGN(sizeof(struct nnot)),
};

static void calcsize(union node *n);

static void
sizenodelist(struct nodelist *lp)
{
	while (lp) {
		funcblocksize += SHELL_ALIGN(sizeof(struct nodelist));
		calcsize(lp->n);
		lp = lp->next;
	}
}

static void
calcsize(union node *n)
{
	if (n == NULL)
		return;
	funcblocksize += nodesize[n->type];
	switch (n->type) {
	case NCMD:
		calcsize(n->ncmd.redirect);
		calcsize(n->ncmd.args);
		calcsize(n->ncmd.assign);
		break;
	case NPIPE:
		sizenodelist(n->npipe.cmdlist);
		break;
	case NREDIR:
	case NBACKGND:
	case NSUBSHELL:
		calcsize(n->nredir.redirect);
		calcsize(n->nredir.n);
		break;
	case NAND:
	case NOR:
	case NSEMI:
	case NWHILE:
	case NUNTIL:
		calcsize(n->nbinary.ch2);
		calcsize(n->nbinary.ch1);
		break;
	case NIF:
		calcsize(n->nif.elsepart);
		calcsize(n->nif.ifpart);
		calcsize(n->nif.test);
		break;
	case NFOR:
		funcstringsize += strlen(n->nfor.var) + 1;
		calcsize(n->nfor.body);
		calcsize(n->nfor.args);
		break;
	case NCASE:
		calcsize(n->ncase.cases);
		calcsize(n->ncase.expr);
		break;
	case NCLIST:
		calcsize(n->nclist.body);
		calcsize(n->nclist.pattern);
		calcsize(n->nclist.next);
		break;
	case NDEFUN:
	case NARG:
		sizenodelist(n->narg.backquote);
		funcstringsize += strlen(n->narg.text) + 1;
		calcsize(n->narg.next);
		break;
	case NTO:
	case NCLOBBER:
	case NFROM:
	case NFROMTO:
	case NAPPEND:
		calcsize(n->nfile.fname);
		calcsize(n->nfile.next);
		break;
	case NTOFD:
	case NFROMFD:
		calcsize(n->ndup.vname);
		calcsize(n->ndup.next);
	break;
	case NHERE:
	case NXHERE:
		calcsize(n->nhere.doc);
		calcsize(n->nhere.next);
		break;
	case NNOT:
		calcsize(n->nnot.com);
		break;
	};
}

static char *
nodeckstrdup(char *s)
{
	char *rtn = funcstring;

	strcpy(funcstring, s);
	funcstring += strlen(s) + 1;
	return rtn;
}

static union node *copynode(union node *);

static struct nodelist *
copynodelist(struct nodelist *lp)
{
	struct nodelist *start;
	struct nodelist **lpp;

	lpp = &start;
	while (lp) {
		*lpp = funcblock;
		funcblock = (char *) funcblock + SHELL_ALIGN(sizeof(struct nodelist));
		(*lpp)->n = copynode(lp->n);
		lp = lp->next;
		lpp = &(*lpp)->next;
	}
	*lpp = NULL;
	return start;
}

static union node *
copynode(union node *n)
{
	union node *new;

	if (n == NULL)
		return NULL;
	new = funcblock;
	funcblock = (char *) funcblock + nodesize[n->type];

	switch (n->type) {
	case NCMD:
		new->ncmd.redirect = copynode(n->ncmd.redirect);
		new->ncmd.args = copynode(n->ncmd.args);
		new->ncmd.assign = copynode(n->ncmd.assign);
		break;
	case NPIPE:
		new->npipe.cmdlist = copynodelist(n->npipe.cmdlist);
		new->npipe.backgnd = n->npipe.backgnd;
		break;
	case NREDIR:
	case NBACKGND:
	case NSUBSHELL:
		new->nredir.redirect = copynode(n->nredir.redirect);
		new->nredir.n = copynode(n->nredir.n);
		break;
	case NAND:
	case NOR:
	case NSEMI:
	case NWHILE:
	case NUNTIL:
		new->nbinary.ch2 = copynode(n->nbinary.ch2);
		new->nbinary.ch1 = copynode(n->nbinary.ch1);
		break;
	case NIF:
		new->nif.elsepart = copynode(n->nif.elsepart);
		new->nif.ifpart = copynode(n->nif.ifpart);
		new->nif.test = copynode(n->nif.test);
		break;
	case NFOR:
		new->nfor.var = nodeckstrdup(n->nfor.var);
		new->nfor.body = copynode(n->nfor.body);
		new->nfor.args = copynode(n->nfor.args);
		break;
	case NCASE:
		new->ncase.cases = copynode(n->ncase.cases);
		new->ncase.expr = copynode(n->ncase.expr);
		break;
	case NCLIST:
		new->nclist.body = copynode(n->nclist.body);
		new->nclist.pattern = copynode(n->nclist.pattern);
		new->nclist.next = copynode(n->nclist.next);
		break;
	case NDEFUN:
	case NARG:
		new->narg.backquote = copynodelist(n->narg.backquote);
		new->narg.text = nodeckstrdup(n->narg.text);
		new->narg.next = copynode(n->narg.next);
		break;
	case NTO:
	case NCLOBBER:
	case NFROM:
	case NFROMTO:
	case NAPPEND:
		new->nfile.fname = copynode(n->nfile.fname);
		new->nfile.fd = n->nfile.fd;
		new->nfile.next = copynode(n->nfile.next);
		break;
	case NTOFD:
	case NFROMFD:
		new->ndup.vname = copynode(n->ndup.vname);
		new->ndup.dupfd = n->ndup.dupfd;
		new->ndup.fd = n->ndup.fd;
		new->ndup.next = copynode(n->ndup.next);
		break;
	case NHERE:
	case NXHERE:
		new->nhere.doc = copynode(n->nhere.doc);
		new->nhere.fd = n->nhere.fd;
		new->nhere.next = copynode(n->nhere.next);
		break;
	case NNOT:
		new->nnot.com = copynode(n->nnot.com);
		break;
	};
	new->type = n->type;
	return new;
}

/*
 * Make a copy of a parse tree.
 */
static struct funcnode *
copyfunc(union node *n)
{
	struct funcnode *f;
	size_t blocksize;

	funcblocksize = offsetof(struct funcnode, n);
	funcstringsize = 0;
	calcsize(n);
	blocksize = funcblocksize;
	f = ckmalloc(blocksize + funcstringsize);
	funcblock = (char *) f + offsetof(struct funcnode, n);
	funcstring = (char *) f + blocksize;
	copynode(n);
	f->count = 0;
	return f;
}

/*
 * Define a shell function.
 */
static void
defun(char *name, union node *func)
{
	struct cmdentry entry;

	INT_OFF;
	entry.cmdtype = CMDFUNCTION;
	entry.u.func = copyfunc(func);
	addcmdentry(name, &entry);
	INT_ON;
}

static int evalskip;            /* set if we are skipping commands */
/* reasons for skipping commands (see comment on breakcmd routine) */
#define SKIPBREAK      (1 << 0)
#define SKIPCONT       (1 << 1)
#define SKIPFUNC       (1 << 2)
#define SKIPFILE       (1 << 3)
#define SKIPEVAL       (1 << 4)
static int skipcount;           /* number of levels to skip */
static int funcnest;            /* depth of function calls */

/* forward decl way out to parsing code - dotrap needs it */
static int evalstring(char *s, int mask);

/*
 * Called to execute a trap.  Perhaps we should avoid entering new trap
 * handlers while we are executing a trap handler.
 */
static int
dotrap(void)
{
	char *p;
	char *q;
	int i;
	int savestatus;
	int skip = 0;

	savestatus = exitstatus;
	pendingsigs = 0;
	xbarrier();

	for (i = 0, q = gotsig; i < NSIG - 1; i++, q++) {
		if (!*q)
			continue;
		*q = '\0';

		p = trap[i + 1];
		if (!p)
			continue;
		skip = evalstring(p, SKIPEVAL);
		exitstatus = savestatus;
		if (skip)
			break;
	}

	return skip;
}

/* forward declarations - evaluation is fairly recursive business... */
static void evalloop(union node *, int);
static void evalfor(union node *, int);
static void evalcase(union node *, int);
static void evalsubshell(union node *, int);
static void expredir(union node *);
static void evalpipe(union node *, int);
static void evalcommand(union node *, int);
static int evalbltin(const struct builtincmd *, int, char **);
static void prehash(union node *);

/*
 * Evaluate a parse tree.  The value is left in the global variable
 * exitstatus.
 */
static void
evaltree(union node *n, int flags)
{
	int checkexit = 0;
	void (*evalfn)(union node *, int);
	unsigned isor;
	int status;
	if (n == NULL) {
		TRACE(("evaltree(NULL) called\n"));
		goto out;
	}
	TRACE(("pid %d, evaltree(%p: %d, %d) called\n",
			getpid(), n, n->type, flags));
	switch (n->type) {
	default:
#if DEBUG
		out1fmt("Node type = %d\n", n->type);
		fflush(stdout);
		break;
#endif
	case NNOT:
		evaltree(n->nnot.com, EV_TESTED);
		status = !exitstatus;
		goto setstatus;
	case NREDIR:
		expredir(n->nredir.redirect);
		status = redirectsafe(n->nredir.redirect, REDIR_PUSH);
		if (!status) {
			evaltree(n->nredir.n, flags & EV_TESTED);
			status = exitstatus;
		}
		popredir(0);
		goto setstatus;
	case NCMD:
		evalfn = evalcommand;
 checkexit:
		if (eflag && !(flags & EV_TESTED))
			checkexit = ~0;
		goto calleval;
	case NFOR:
		evalfn = evalfor;
		goto calleval;
	case NWHILE:
	case NUNTIL:
		evalfn = evalloop;
		goto calleval;
	case NSUBSHELL:
	case NBACKGND:
		evalfn = evalsubshell;
		goto calleval;
	case NPIPE:
		evalfn = evalpipe;
		goto checkexit;
	case NCASE:
		evalfn = evalcase;
		goto calleval;
	case NAND:
	case NOR:
	case NSEMI:
#if NAND + 1 != NOR
#error NAND + 1 != NOR
#endif
#if NOR + 1 != NSEMI
#error NOR + 1 != NSEMI
#endif
		isor = n->type - NAND;
		evaltree(
			n->nbinary.ch1,
			(flags | ((isor >> 1) - 1)) & EV_TESTED
		);
		if (!exitstatus == isor)
			break;
		if (!evalskip) {
			n = n->nbinary.ch2;
 evaln:
			evalfn = evaltree;
 calleval:
			evalfn(n, flags);
			break;
		}
		break;
	case NIF:
		evaltree(n->nif.test, EV_TESTED);
		if (evalskip)
			break;
		if (exitstatus == 0) {
			n = n->nif.ifpart;
			goto evaln;
		} else if (n->nif.elsepart) {
			n = n->nif.elsepart;
			goto evaln;
		}
		goto success;
	case NDEFUN:
		defun(n->narg.text, n->narg.next);
 success:
		status = 0;
 setstatus:
		exitstatus = status;
		break;
	}
 out:
	if ((checkexit & exitstatus))
		evalskip |= SKIPEVAL;
	else if (pendingsigs && dotrap())
		goto exexit;

	if (flags & EV_EXIT) {
 exexit:
		raise_exception(EXEXIT);
	}
}

#if !defined(__alpha__) || (defined(__GNUC__) && __GNUC__ >= 3)
static
#endif
void evaltreenr(union node *, int) __attribute__ ((alias("evaltree"),__noreturn__));

static int loopnest;            /* current loop nesting level */

static void
evalloop(union node *n, int flags)
{
	int status;

	loopnest++;
	status = 0;
	flags &= EV_TESTED;
	for (;;) {
		int i;

		evaltree(n->nbinary.ch1, EV_TESTED);
		if (evalskip) {
 skipping:
			if (evalskip == SKIPCONT && --skipcount <= 0) {
				evalskip = 0;
				continue;
			}
			if (evalskip == SKIPBREAK && --skipcount <= 0)
				evalskip = 0;
			break;
		}
		i = exitstatus;
		if (n->type != NWHILE)
			i = !i;
		if (i != 0)
			break;
		evaltree(n->nbinary.ch2, flags);
		status = exitstatus;
		if (evalskip)
			goto skipping;
	}
	loopnest--;
	exitstatus = status;
}

static void
evalfor(union node *n, int flags)
{
	struct arglist arglist;
	union node *argp;
	struct strlist *sp;
	struct stackmark smark;

	setstackmark(&smark);
	arglist.lastp = &arglist.list;
	for (argp = n->nfor.args; argp; argp = argp->narg.next) {
		expandarg(argp, &arglist, EXP_FULL | EXP_TILDE | EXP_RECORD);
		/* XXX */
		if (evalskip)
			goto out;
	}
	*arglist.lastp = NULL;

	exitstatus = 0;
	loopnest++;
	flags &= EV_TESTED;
	for (sp = arglist.list; sp; sp = sp->next) {
		setvar(n->nfor.var, sp->text, 0);
		evaltree(n->nfor.body, flags);
		if (evalskip) {
			if (evalskip == SKIPCONT && --skipcount <= 0) {
				evalskip = 0;
				continue;
			}
			if (evalskip == SKIPBREAK && --skipcount <= 0)
				evalskip = 0;
			break;
		}
	}
	loopnest--;
 out:
	popstackmark(&smark);
}

static void
evalcase(union node *n, int flags)
{
	union node *cp;
	union node *patp;
	struct arglist arglist;
	struct stackmark smark;

	setstackmark(&smark);
	arglist.lastp = &arglist.list;
	expandarg(n->ncase.expr, &arglist, EXP_TILDE);
	exitstatus = 0;
	for (cp = n->ncase.cases; cp && evalskip == 0; cp = cp->nclist.next) {
		for (patp = cp->nclist.pattern; patp; patp = patp->narg.next) {
			if (casematch(patp, arglist.list->text)) {
				if (evalskip == 0) {
					evaltree(cp->nclist.body, flags);
				}
				goto out;
			}
		}
	}
 out:
	popstackmark(&smark);
}

/*
 * Kick off a subshell to evaluate a tree.
 */
static void
evalsubshell(union node *n, int flags)
{
	struct job *jp;
	int backgnd = (n->type == NBACKGND);
	int status;

	expredir(n->nredir.redirect);
	if (!backgnd && flags & EV_EXIT && !trap[0])
		goto nofork;
	INT_OFF;
	jp = makejob(n, 1);
	if (forkshell(jp, n, backgnd) == 0) {
		INT_ON;
		flags |= EV_EXIT;
		if (backgnd)
			flags &=~ EV_TESTED;
 nofork:
		redirect(n->nredir.redirect, 0);
		evaltreenr(n->nredir.n, flags);
		/* never returns */
	}
	status = 0;
	if (! backgnd)
		status = waitforjob(jp);
	exitstatus = status;
	INT_ON;
}

/*
 * Compute the names of the files in a redirection list.
 */
static void fixredir(union node *, const char *, int);
static void
expredir(union node *n)
{
	union node *redir;

	for (redir = n; redir; redir = redir->nfile.next) {
		struct arglist fn;

		memset(&fn, 0, sizeof(fn));
		fn.lastp = &fn.list;
		switch (redir->type) {
		case NFROMTO:
		case NFROM:
		case NTO:
		case NCLOBBER:
		case NAPPEND:
			expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
			redir->nfile.expfname = fn.list->text;
			break;
		case NFROMFD:
		case NTOFD:
			if (redir->ndup.vname) {
				expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE);
				if (fn.list == NULL)
					ash_msg_and_raise_error("redir error");
				fixredir(redir, fn.list->text, 1);
			}
			break;
		}
	}
}

/*
 * Evaluate a pipeline.  All the processes in the pipeline are children
 * of the process creating the pipeline.  (This differs from some versions
 * of the shell, which make the last process in a pipeline the parent
 * of all the rest.)
 */
static void
evalpipe(union node *n, int flags)
{
	struct job *jp;
	struct nodelist *lp;
	int pipelen;
	int prevfd;
	int pip[2];

	TRACE(("evalpipe(0x%lx) called\n", (long)n));
	pipelen = 0;
	for (lp = n->npipe.cmdlist; lp; lp = lp->next)
		pipelen++;
	flags |= EV_EXIT;
	INT_OFF;
	jp = makejob(n, pipelen);
	prevfd = -1;
	for (lp = n->npipe.cmdlist; lp; lp = lp->next) {
		prehash(lp->n);
		pip[1] = -1;
		if (lp->next) {
			if (pipe(pip) < 0) {
				close(prevfd);
				ash_msg_and_raise_error("pipe call failed");
			}
		}
		if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) {
			INT_ON;
			if (pip[1] >= 0) {
				close(pip[0]);
			}
			if (prevfd > 0) {
				dup2(prevfd, 0);
				close(prevfd);
			}
			if (pip[1] > 1) {
				dup2(pip[1], 1);
				close(pip[1]);
			}
			evaltreenr(lp->n, flags);
			/* never returns */
		}
		if (prevfd >= 0)
			close(prevfd);
		prevfd = pip[0];
		close(pip[1]);
	}
	if (n->npipe.backgnd == 0) {
		exitstatus = waitforjob(jp);
		TRACE(("evalpipe:  job done exit status %d\n", exitstatus));
	}
	INT_ON;
}

/*
 * Controls whether the shell is interactive or not.
 */
static void
setinteractive(int on)
{
	static int is_interactive;

	if (++on == is_interactive)
		return;
	is_interactive = on;
	setsignal(SIGINT);
	setsignal(SIGQUIT);
	setsignal(SIGTERM);
#if !ENABLE_FEATURE_SH_EXTRA_QUIET
	if (is_interactive > 1) {
		/* Looks like they want an interactive shell */
		static smallint do_banner;

		if (!do_banner) {
			out1fmt(
				"\n\n"
				"%s Built-in shell (ash)\n"
				"Enter 'help' for a list of built-in commands."
				"\n\n",
				BB_BANNER);
			do_banner = 1;
		}
	}
#endif
}

#if ENABLE_FEATURE_EDITING_VI
#define setvimode(on) do { \
	if (on) line_input_state->flags |= VI_MODE; \
	else line_input_state->flags &= ~VI_MODE; \
} while (0)
#else
#define setvimode(on) viflag = 0   /* forcibly keep the option off */
#endif

static void
optschanged(void)
{
#if DEBUG
	opentrace();
#endif
	setinteractive(iflag);
	setjobctl(mflag);
	setvimode(viflag);
}

static struct localvar *localvars;

/*
 * Called after a function returns.
 * Interrupts must be off.
 */
static void
poplocalvars(void)
{
	struct localvar *lvp;
	struct var *vp;

	while ((lvp = localvars) != NULL) {
		localvars = lvp->next;
		vp = lvp->vp;
		TRACE(("poplocalvar %s", vp ? vp->text : "-"));
		if (vp == NULL) {       /* $- saved */
			memcpy(optlist, lvp->text, sizeof(optlist));
			free((char*)lvp->text);
			optschanged();
		} else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
			unsetvar(vp->text);
		} else {
			if (vp->func)
				(*vp->func)(strchrnul(lvp->text, '=') + 1);
			if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
				free((char*)vp->text);
			vp->flags = lvp->flags;
			vp->text = lvp->text;
		}
		free(lvp);
	}
}

static int
evalfun(struct funcnode *func, int argc, char **argv, int flags)
{
	volatile struct shparam saveparam;
	struct localvar *volatile savelocalvars;
	struct jmploc *volatile savehandler;
	struct jmploc jmploc;
	int e;

	saveparam = shellparam;
	savelocalvars = localvars;
	e = setjmp(jmploc.loc);
	if (e) {
		goto funcdone;
	}
	INT_OFF;
	savehandler = exception_handler;
	exception_handler = &jmploc;
	localvars = NULL;
	shellparam.malloc = 0;
	func->count++;
	funcnest++;
	INT_ON;
	shellparam.nparam = argc - 1;
	shellparam.p = argv + 1;
#if ENABLE_ASH_GETOPTS
	shellparam.optind = 1;
	shellparam.optoff = -1;
#endif
	evaltree(&func->n, flags & EV_TESTED);
funcdone:
	INT_OFF;
	funcnest--;
	freefunc(func);
	poplocalvars();
	localvars = savelocalvars;
	freeparam(&shellparam);
	shellparam = saveparam;
	exception_handler = savehandler;
	INT_ON;
	evalskip &= ~SKIPFUNC;
	return e;
}

#if ENABLE_ASH_CMDCMD
static char **
parse_command_args(char **argv, const char **path)
{
	char *cp, c;

	for (;;) {
		cp = *++argv;
		if (!cp)
			return 0;
		if (*cp++ != '-')
			break;
		c = *cp++;
		if (!c)
			break;
		if (c == '-' && !*cp) {
			argv++;
			break;
		}
		do {
			switch (c) {
			case 'p':
				*path = defpath;
				break;
			default:
				/* run 'typecmd' for other options */
				return 0;
			}
			c = *cp++;
		} while (c);
	}
	return argv;
}
#endif

/*
 * Make a variable a local variable.  When a variable is made local, it's
 * value and flags are saved in a localvar structure.  The saved values
 * will be restored when the shell function returns.  We handle the name
 * "-" as a special case.
 */
static void
mklocal(char *name)
{
	struct localvar *lvp;
	struct var **vpp;
	struct var *vp;

	INT_OFF;
	lvp = ckmalloc(sizeof(struct localvar));
	if (LONE_DASH(name)) {
		char *p;
		p = ckmalloc(sizeof(optlist));
		lvp->text = memcpy(p, optlist, sizeof(optlist));
		vp = NULL;
	} else {
		char *eq;

		vpp = hashvar(name);
		vp = *findvar(vpp, name);
		eq = strchr(name, '=');
		if (vp == NULL) {
			if (eq)
				setvareq(name, VSTRFIXED);
			else
				setvar(name, NULL, VSTRFIXED);
			vp = *vpp;      /* the new variable */
			lvp->flags = VUNSET;
		} else {
			lvp->text = vp->text;
			lvp->flags = vp->flags;
			vp->flags |= VSTRFIXED|VTEXTFIXED;
			if (eq)
				setvareq(name, 0);
		}
	}
	lvp->vp = vp;
	lvp->next = localvars;
	localvars = lvp;
	INT_ON;
}

/*
 * The "local" command.
 */
static int
localcmd(int argc, char **argv)
{
	char *name;

	argv = argptr;
	while ((name = *argv++) != NULL) {
		mklocal(name);
	}
	return 0;
}

static int
falsecmd(int argc, char **argv)
{
	return 1;
}

static int
truecmd(int argc, char **argv)
{
	return 0;
}

static int
execcmd(int argc, char **argv)
{
	if (argc > 1) {
		iflag = 0;              /* exit on error */
		mflag = 0;
		optschanged();
		shellexec(argv + 1, pathval(), 0);
	}
	return 0;
}

/*
 * The return command.
 */
static int
returncmd(int argc, char **argv)
{
	/*
	 * If called outside a function, do what ksh does;
	 * skip the rest of the file.
	 */
	evalskip = funcnest ? SKIPFUNC : SKIPFILE;
	return argv[1] ? number(argv[1]) : exitstatus;
}

/* Forward declarations for builtintab[] */
static int breakcmd(int, char **);
static int dotcmd(int, char **);
static int evalcmd(int, char **);
#if ENABLE_ASH_BUILTIN_ECHO
static int echocmd(int, char **);
#endif
#if ENABLE_ASH_BUILTIN_TEST
static int testcmd(int, char **);
#endif
static int exitcmd(int, char **);
static int exportcmd(int, char **);
#if ENABLE_ASH_GETOPTS
static int getoptscmd(int, char **);
#endif
#if !ENABLE_FEATURE_SH_EXTRA_QUIET
static int helpcmd(int argc, char **argv);
#endif
#if ENABLE_ASH_MATH_SUPPORT
static int letcmd(int, char **);
#endif
static int readcmd(int, char **);
static int setcmd(int, char **);
static int shiftcmd(int, char **);
static int timescmd(int, char **);
static int trapcmd(int, char **);
static int umaskcmd(int, char **);
static int unsetcmd(int, char **);
static int ulimitcmd(int, char **);

#define BUILTIN_NOSPEC          "0"
#define BUILTIN_SPECIAL         "1"
#define BUILTIN_REGULAR         "2"
#define BUILTIN_SPEC_REG        "3"
#define BUILTIN_ASSIGN          "4"
#define BUILTIN_SPEC_ASSG       "5"
#define BUILTIN_REG_ASSG        "6"
#define BUILTIN_SPEC_REG_ASSG   "7"

/* make sure to keep these in proper order since it is searched via bsearch() */
static const struct builtincmd builtintab[] = {
	{ BUILTIN_SPEC_REG      ".", dotcmd },
	{ BUILTIN_SPEC_REG      ":", truecmd },
#if ENABLE_ASH_BUILTIN_TEST
	{ BUILTIN_REGULAR	"[", testcmd },
	{ BUILTIN_REGULAR	"[[", testcmd },
#endif
#if ENABLE_ASH_ALIAS
	{ BUILTIN_REG_ASSG      "alias", aliascmd },
#endif
#if JOBS
	{ BUILTIN_REGULAR       "bg", fg_bgcmd },
#endif
	{ BUILTIN_SPEC_REG      "break", breakcmd },
	{ BUILTIN_REGULAR       "cd", cdcmd },
	{ BUILTIN_NOSPEC        "chdir", cdcmd },
#if ENABLE_ASH_CMDCMD
	{ BUILTIN_REGULAR       "command", commandcmd },
#endif
	{ BUILTIN_SPEC_REG      "continue", breakcmd },
#if ENABLE_ASH_BUILTIN_ECHO
	{ BUILTIN_REGULAR       "echo", echocmd },
#endif
	{ BUILTIN_SPEC_REG      "eval", evalcmd },
	{ BUILTIN_SPEC_REG      "exec", execcmd },
	{ BUILTIN_SPEC_REG      "exit", exitcmd },
	{ BUILTIN_SPEC_REG_ASSG "export", exportcmd },
	{ BUILTIN_REGULAR       "false", falsecmd },
#if JOBS
	{ BUILTIN_REGULAR       "fg", fg_bgcmd },
#endif
#if ENABLE_ASH_GETOPTS
	{ BUILTIN_REGULAR       "getopts", getoptscmd },
#endif
	{ BUILTIN_NOSPEC        "hash", hashcmd },
#if !ENABLE_FEATURE_SH_EXTRA_QUIET
	{ BUILTIN_NOSPEC        "help", helpcmd },
#endif
#if JOBS
	{ BUILTIN_REGULAR       "jobs", jobscmd },
	{ BUILTIN_REGULAR       "kill", killcmd },
#endif
#if ENABLE_ASH_MATH_SUPPORT
	{ BUILTIN_NOSPEC        "let", letcmd },
#endif
	{ BUILTIN_ASSIGN        "local", localcmd },
	{ BUILTIN_NOSPEC        "pwd", pwdcmd },
	{ BUILTIN_REGULAR       "read", readcmd },
	{ BUILTIN_SPEC_REG_ASSG "readonly", exportcmd },
	{ BUILTIN_SPEC_REG      "return", returncmd },
	{ BUILTIN_SPEC_REG      "set", setcmd },
	{ BUILTIN_SPEC_REG      "shift", shiftcmd },
	{ BUILTIN_SPEC_REG      "source", dotcmd },
#if ENABLE_ASH_BUILTIN_TEST
	{ BUILTIN_REGULAR	"test", testcmd },
#endif
	{ BUILTIN_SPEC_REG      "times", timescmd },
	{ BUILTIN_SPEC_REG      "trap", trapcmd },
	{ BUILTIN_REGULAR       "true", truecmd },
	{ BUILTIN_NOSPEC        "type", typecmd },
	{ BUILTIN_NOSPEC        "ulimit", ulimitcmd },
	{ BUILTIN_REGULAR       "umask", umaskcmd },
#if ENABLE_ASH_ALIAS
	{ BUILTIN_REGULAR       "unalias", unaliascmd },
#endif
	{ BUILTIN_SPEC_REG      "unset", unsetcmd },
	{ BUILTIN_REGULAR       "wait", waitcmd },
};

#define NUMBUILTINS (sizeof(builtintab) / sizeof(builtintab[0]))

#define COMMANDCMD (builtintab + 5 + \
	2 * ENABLE_ASH_BUILTIN_TEST + \
	ENABLE_ASH_ALIAS + \
	ENABLE_ASH_JOB_CONTROL)
#define EXECCMD (builtintab + 7 + \
	2 * ENABLE_ASH_BUILTIN_TEST + \
	ENABLE_ASH_ALIAS + \
	ENABLE_ASH_JOB_CONTROL + \
	ENABLE_ASH_CMDCMD + \
	ENABLE_ASH_BUILTIN_ECHO)

/*
 * Search the table of builtin commands.
 */
static struct builtincmd *
find_builtin(const char *name)
{
	struct builtincmd *bp;

	bp = bsearch(
		name, builtintab, NUMBUILTINS, sizeof(builtintab[0]),
		pstrcmp
	);
	return bp;
}

/*
 * Execute a simple command.
 */
static int back_exitstatus; /* exit status of backquoted command */
static int
isassignment(const char *p)
{
	const char *q = endofname(p);
	if (p == q)
		return 0;
	return *q == '=';
}
static int
bltincmd(int argc, char **argv)
{
	/* Preserve exitstatus of a previous possible redirection
	 * as POSIX mandates */
	return back_exitstatus;
}
static void
evalcommand(union node *cmd, int flags)
{
	static const struct builtincmd bltin = {
		"\0\0", bltincmd
	};
	struct stackmark smark;
	union node *argp;
	struct arglist arglist;
	struct arglist varlist;
	char **argv;
	int argc;
	const struct strlist *sp;
	struct cmdentry cmdentry;
	struct job *jp;
	char *lastarg;
	const char *path;
	int spclbltin;
	int cmd_is_exec;
	int status;
	char **nargv;
	struct builtincmd *bcmd;
	int pseudovarflag = 0;

	/* First expand the arguments. */
	TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
	setstackmark(&smark);
	back_exitstatus = 0;

	cmdentry.cmdtype = CMDBUILTIN;
	cmdentry.u.cmd = &bltin;
	varlist.lastp = &varlist.list;
	*varlist.lastp = NULL;
	arglist.lastp = &arglist.list;
	*arglist.lastp = NULL;

	argc = 0;
	if (cmd->ncmd.args) {
		bcmd = find_builtin(cmd->ncmd.args->narg.text);
		pseudovarflag = bcmd && IS_BUILTIN_ASSIGN(bcmd);
	}

	for (argp = cmd->ncmd.args; argp; argp = argp->narg.next) {
		struct strlist **spp;

		spp = arglist.lastp;
		if (pseudovarflag && isassignment(argp->narg.text))
			expandarg(argp, &arglist, EXP_VARTILDE);
		else
			expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);

		for (sp = *spp; sp; sp = sp->next)
			argc++;
	}

	argv = nargv = stalloc(sizeof(char *) * (argc + 1));
	for (sp = arglist.list; sp; sp = sp->next) {
		TRACE(("evalcommand arg: %s\n", sp->text));
		*nargv++ = sp->text;
	}
	*nargv = NULL;

	lastarg = NULL;
	if (iflag && funcnest == 0 && argc > 0)
		lastarg = nargv[-1];

	preverrout_fd = 2;
	expredir(cmd->ncmd.redirect);
	status = redirectsafe(cmd->ncmd.redirect, REDIR_PUSH | REDIR_SAVEFD2);

	path = vpath.text;
	for (argp = cmd->ncmd.assign; argp; argp = argp->narg.next) {
		struct strlist **spp;
		char *p;

		spp = varlist.lastp;
		expandarg(argp, &varlist, EXP_VARTILDE);

		/*
		 * Modify the command lookup path, if a PATH= assignment
		 * is present
		 */
		p = (*spp)->text;
		if (varequal(p, path))
			path = p;
	}

	/* Print the command if xflag is set. */
	if (xflag) {
		int n;
		const char *p = " %s";

		p++;
		dprintf(preverrout_fd, p, expandstr(ps4val()));

		sp = varlist.list;
		for (n = 0; n < 2; n++) {
			while (sp) {
				dprintf(preverrout_fd, p, sp->text);
				sp = sp->next;
				if (*p == '%') {
					p--;
				}
			}
			sp = arglist.list;
		}
		full_write(preverrout_fd, "\n", 1);
	}

	cmd_is_exec = 0;
	spclbltin = -1;

	/* Now locate the command. */
	if (argc) {
		const char *oldpath;
		int cmd_flag = DO_ERR;

		path += 5;
		oldpath = path;
		for (;;) {
			find_command(argv[0], &cmdentry, cmd_flag, path);
			if (cmdentry.cmdtype == CMDUNKNOWN) {
				status = 127;
				flush_stderr();
				goto bail;
			}

			/* implement bltin and command here */
			if (cmdentry.cmdtype != CMDBUILTIN)
				break;
			if (spclbltin < 0)
				spclbltin = IS_BUILTIN_SPECIAL(cmdentry.u.cmd);
			if (cmdentry.u.cmd == EXECCMD)
				cmd_is_exec++;
#if ENABLE_ASH_CMDCMD
			if (cmdentry.u.cmd == COMMANDCMD) {
				path = oldpath;
				nargv = parse_command_args(argv, &path);
				if (!nargv)
					break;
				argc -= nargv - argv;
				argv = nargv;
				cmd_flag |= DO_NOFUNC;
			} else
#endif
				break;
		}
	}

	if (status) {
		/* We have a redirection error. */
		if (spclbltin > 0)
			raise_exception(EXERROR);
 bail:
		exitstatus = status;
		goto out;
	}

	/* Execute the command. */
	switch (cmdentry.cmdtype) {
	default:
		/* Fork off a child process if necessary. */
		if (!(flags & EV_EXIT) || trap[0]) {
			INT_OFF;
			jp = makejob(cmd, 1);
			if (forkshell(jp, cmd, FORK_FG) != 0) {
				exitstatus = waitforjob(jp);
				INT_ON;
				break;
			}
			FORCE_INT_ON;
		}
		listsetvar(varlist.list, VEXPORT|VSTACK);
		shellexec(argv, path, cmdentry.u.index);
		/* NOTREACHED */

	case CMDBUILTIN:
		cmdenviron = varlist.list;
		if (cmdenviron) {
			struct strlist *list = cmdenviron;
			int i = VNOSET;
			if (spclbltin > 0 || argc == 0) {
				i = 0;
				if (cmd_is_exec && argc > 1)
					i = VEXPORT;
			}
			listsetvar(list, i);
		}
		if (evalbltin(cmdentry.u.cmd, argc, argv)) {
			int exit_status;
			int i, j;

			i = exception;
			if (i == EXEXIT)
				goto raise;

			exit_status = 2;
			j = 0;
			if (i == EXINT)
				j = SIGINT;
			if (i == EXSIG)
				j = pendingsigs;
			if (j)
				exit_status = j + 128;
			exitstatus = exit_status;

			if (i == EXINT || spclbltin > 0) {
 raise:
				longjmp(exception_handler->loc, 1);
			}
			FORCE_INT_ON;
		}
		break;

	case CMDFUNCTION:
		listsetvar(varlist.list, 0);
		if (evalfun(cmdentry.u.func, argc, argv, flags))
			goto raise;
		break;
	}

 out:
	popredir(cmd_is_exec);
	if (lastarg)
		/* dsl: I think this is intended to be used to support
		 * '_' in 'vi' command mode during line editing...
		 * However I implemented that within libedit itself.
		 */
		setvar("_", lastarg, 0);
	popstackmark(&smark);
}

static int
evalbltin(const struct builtincmd *cmd, int argc, char **argv)
{
	char *volatile savecmdname;
	struct jmploc *volatile savehandler;
	struct jmploc jmploc;
	int i;

	savecmdname = commandname;
	i = setjmp(jmploc.loc);
	if (i)
		goto cmddone;
	savehandler = exception_handler;
	exception_handler = &jmploc;
	commandname = argv[0];
	argptr = argv + 1;
	optptr = NULL;                  /* initialize nextopt */
	exitstatus = (*cmd->builtin)(argc, argv);
	flush_stdout_stderr();
 cmddone:
	exitstatus |= ferror(stdout);
	clearerr(stdout);
	commandname = savecmdname;
	exsig = 0;
	exception_handler = savehandler;

	return i;
}

static int
goodname(const char *p)
{
	return !*endofname(p);
}


/*
 * Search for a command.  This is called before we fork so that the
 * location of the command will be available in the parent as well as
 * the child.  The check for "goodname" is an overly conservative
 * check that the name will not be subject to expansion.
 */
static void
prehash(union node *n)
{
	struct cmdentry entry;

	if (n->type == NCMD && n->ncmd.args && goodname(n->ncmd.args->narg.text))
		find_command(n->ncmd.args->narg.text, &entry, 0, pathval());
}


/* ============ Builtin commands
 *
 * Builtin commands whose functions are closely tied to evaluation
 * are implemented here.
 */

/*
 * Handle break and continue commands.  Break, continue, and return are
 * all handled by setting the evalskip flag.  The evaluation routines
 * above all check this flag, and if it is set they start skipping
 * commands rather than executing them.  The variable skipcount is
 * the number of loops to break/continue, or the number of function
 * levels to return.  (The latter is always 1.)  It should probably
 * be an error to break out of more loops than exist, but it isn't
 * in the standard shell so we don't make it one here.
 */
static int
breakcmd(int argc, char **argv)
{
	int n = argc > 1 ? number(argv[1]) : 1;

	if (n <= 0)
		ash_msg_and_raise_error(illnum, argv[1]);
	if (n > loopnest)
		n = loopnest;
	if (n > 0) {
		evalskip = (**argv == 'c') ? SKIPCONT : SKIPBREAK;
		skipcount = n;
	}
	return 0;
}


/* ============ input.c
 *
 * This implements the input routines used by the parser.
 */

#define EOF_NLEFT -99           /* value of parsenleft when EOF pushed back */

enum {
	INPUT_PUSH_FILE = 1,
	INPUT_NOFILE_OK = 2,
};

/*
 * NEOF is returned by parsecmd when it encounters an end of file.  It
 * must be distinct from NULL, so we use the address of a variable that
 * happens to be handy.
 */
static int plinno = 1;                  /* input line number */
/* number of characters left in input buffer */
static int parsenleft;                  /* copy of parsefile->nleft */
static int parselleft;                  /* copy of parsefile->lleft */
/* next character in input buffer */
static char *parsenextc;                /* copy of parsefile->nextc */

static int checkkwd;
/* values of checkkwd variable */
#define CHKALIAS        0x1
#define CHKKWD          0x2
#define CHKNL           0x4

static void
popstring(void)
{
	struct strpush *sp = parsefile->strpush;

	INT_OFF;
#if ENABLE_ASH_ALIAS
	if (sp->ap) {
		if (parsenextc[-1] == ' ' || parsenextc[-1] == '\t') {
			checkkwd |= CHKALIAS;
		}
		if (sp->string != sp->ap->val) {
			free(sp->string);
		}
		sp->ap->flag &= ~ALIASINUSE;
		if (sp->ap->flag & ALIASDEAD) {
			unalias(sp->ap->name);
		}
	}
#endif
	parsenextc = sp->prevstring;
	parsenleft = sp->prevnleft;
/*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
	parsefile->strpush = sp->prev;
	if (sp != &(parsefile->basestrpush))
		free(sp);
	INT_ON;
}

static int
preadfd(void)
{
	int nr;
	char *buf =  parsefile->buf;
	parsenextc = buf;

 retry:
#if ENABLE_FEATURE_EDITING
	if (!iflag || parsefile->fd)
		nr = safe_read(parsefile->fd, buf, BUFSIZ - 1);
	else {
#if ENABLE_FEATURE_TAB_COMPLETION
		line_input_state->path_lookup = pathval();
#endif
		nr = read_line_input(cmdedit_prompt, buf, BUFSIZ, line_input_state);
		if (nr == 0) {
			/* Ctrl+C pressed */
			if (trap[SIGINT]) {
				buf[0] = '\n';
				buf[1] = '\0';
				raise(SIGINT);
				return 1;
			}
			goto retry;
		}
		if (nr < 0 && errno == 0) {
			/* Ctrl+D presend */
			nr = 0;
		}
	}
#else
	nr = safe_read(parsefile->fd, buf, BUFSIZ - 1);
#endif

	if (nr < 0) {
		if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
			int flags = fcntl(0, F_GETFL, 0);
			if (flags >= 0 && flags & O_NONBLOCK) {
				flags &=~ O_NONBLOCK;
				if (fcntl(0, F_SETFL, flags) >= 0) {
					out2str("sh: turning off NDELAY mode\n");
					goto retry;
				}
			}
		}
	}
	return nr;
}

/*
 * Refill the input buffer and return the next input character:
 *
 * 1) If a string was pushed back on the input, pop it;
 * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
 *    from a string so we can't refill the buffer, return EOF.
 * 3) If the is more stuff in this buffer, use it else call read to fill it.
 * 4) Process input up to the next newline, deleting nul characters.
 */
static int
preadbuffer(void)
{
	char *q;
	int more;
	char savec;

	while (parsefile->strpush) {
#if ENABLE_ASH_ALIAS
		if (parsenleft == -1 && parsefile->strpush->ap &&
			parsenextc[-1] != ' ' && parsenextc[-1] != '\t') {
			return PEOA;
		}
#endif
		popstring();
		if (--parsenleft >= 0)
			return signed_char2int(*parsenextc++);
	}
	if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
		return PEOF;
	flush_stdout_stderr();

	more = parselleft;
	if (more <= 0) {
 again:
		more = preadfd();
		if (more <= 0) {
			parselleft = parsenleft = EOF_NLEFT;
			return PEOF;
		}
	}

	q = parsenextc;

	/* delete nul characters */
	for (;;) {
		int c;

		more--;
		c = *q;

		if (!c)
			memmove(q, q + 1, more);
		else {
			q++;
			if (c == '\n') {
				parsenleft = q - parsenextc - 1;
				break;
			}
		}

		if (more <= 0) {
			parsenleft = q - parsenextc - 1;
			if (parsenleft < 0)
				goto again;
			break;
		}
	}
	parselleft = more;

	savec = *q;
	*q = '\0';

	if (vflag) {
		out2str(parsenextc);
	}

	*q = savec;

	return signed_char2int(*parsenextc++);
}

#define pgetc_as_macro() (--parsenleft >= 0? signed_char2int(*parsenextc++) : preadbuffer())
static int
pgetc(void)
{
	return pgetc_as_macro();
}

#if ENABLE_ASH_OPTIMIZE_FOR_SIZE
#define pgetc_macro() pgetc()
#else
#define pgetc_macro() pgetc_as_macro()
#endif

/*
 * Same as pgetc(), but ignores PEOA.
 */
#if ENABLE_ASH_ALIAS
static int
pgetc2(void)
{
	int c;

	do {
		c = pgetc_macro();
	} while (c == PEOA);
	return c;
}
#else
static int
pgetc2(void)
{
	return pgetc_macro();
}
#endif

/*
 * Read a line from the script.
 */
static char *
pfgets(char *line, int len)
{
	char *p = line;
	int nleft = len;
	int c;

	while (--nleft > 0) {
		c = pgetc2();
		if (c == PEOF) {
			if (p == line)
				return NULL;
			break;
		}
		*p++ = c;
		if (c == '\n')
			break;
	}
	*p = '\0';
	return line;
}

/*
 * Undo the last call to pgetc.  Only one character may be pushed back.
 * PEOF may be pushed back.
 */
static void
pungetc(void)
{
	parsenleft++;
	parsenextc--;
}

/*
 * Push a string back onto the input at this current parsefile level.
 * We handle aliases this way.
 */
static void
pushstring(char *s, void *ap)
{
	struct strpush *sp;
	size_t len;

	len = strlen(s);
	INT_OFF;
/*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
	if (parsefile->strpush) {
		sp = ckmalloc(sizeof(struct strpush));
		sp->prev = parsefile->strpush;
		parsefile->strpush = sp;
	} else
		sp = parsefile->strpush = &(parsefile->basestrpush);
	sp->prevstring = parsenextc;
	sp->prevnleft = parsenleft;
#if ENABLE_ASH_ALIAS
	sp->ap = (struct alias *)ap;
	if (ap) {
		((struct alias *)ap)->flag |= ALIASINUSE;
		sp->string = s;
	}
#endif
	parsenextc = s;
	parsenleft = len;
	INT_ON;
}

/*
 * To handle the "." command, a stack of input files is used.  Pushfile
 * adds a new entry to the stack and popfile restores the previous level.
 */
static void
pushfile(void)
{
	struct parsefile *pf;

	parsefile->nleft = parsenleft;
	parsefile->lleft = parselleft;
	parsefile->nextc = parsenextc;
	parsefile->linno = plinno;
	pf = ckmalloc(sizeof(*pf));
	pf->prev = parsefile;
	pf->fd = -1;
	pf->strpush = NULL;
	pf->basestrpush.prev = NULL;
	parsefile = pf;
}

static void
popfile(void)
{
	struct parsefile *pf = parsefile;

	INT_OFF;
	if (pf->fd >= 0)
		close(pf->fd);
	if (pf->buf)
		free(pf->buf);
	while (pf->strpush)
		popstring();
	parsefile = pf->prev;
	free(pf);
	parsenleft = parsefile->nleft;
	parselleft = parsefile->lleft;
	parsenextc = parsefile->nextc;
	plinno = parsefile->linno;
	INT_ON;
}

/*
 * Return to top level.
 */
static void
popallfiles(void)
{
	while (parsefile != &basepf)
		popfile();
}

/*
 * Close the file(s) that the shell is reading commands from.  Called
 * after a fork is done.
 */
static void
closescript(void)
{
	popallfiles();
	if (parsefile->fd > 0) {
		close(parsefile->fd);
		parsefile->fd = 0;
	}
}

/*
 * Like setinputfile, but takes an open file descriptor.  Call this with
 * interrupts off.
 */
static void
setinputfd(int fd, int push)
{
	fcntl(fd, F_SETFD, FD_CLOEXEC);
	if (push) {
		pushfile();
		parsefile->buf = 0;
	}
	parsefile->fd = fd;
	if (parsefile->buf == NULL)
		parsefile->buf = ckmalloc(IBUFSIZ);
	parselleft = parsenleft = 0;
	plinno = 1;
}

/*
 * Set the input to take input from a file.  If push is set, push the
 * old input onto the stack first.
 */
static int
setinputfile(const char *fname, int flags)
{
	int fd;
	int fd2;

	INT_OFF;
	fd = open(fname, O_RDONLY);
	if (fd < 0) {
		if (flags & INPUT_NOFILE_OK)
			goto out;
		ash_msg_and_raise_error("can't open %s", fname);
	}
	if (fd < 10) {
		fd2 = copyfd(fd, 10);
		close(fd);
		if (fd2 < 0)
			ash_msg_and_raise_error("out of file descriptors");
		fd = fd2;
	}
	setinputfd(fd, flags & INPUT_PUSH_FILE);
 out:
	INT_ON;
	return fd;
}

/*
 * Like setinputfile, but takes input from a string.
 */
static void
setinputstring(char *string)
{
	INT_OFF;
	pushfile();
	parsenextc = string;
	parsenleft = strlen(string);
	parsefile->buf = NULL;
	plinno = 1;
	INT_ON;
}


/* ============ mail.c
 *
 * Routines to check for mail.
 */

#if ENABLE_ASH_MAIL

#define MAXMBOXES 10

/* times of mailboxes */
static time_t mailtime[MAXMBOXES];
/* Set if MAIL or MAILPATH is changed. */
static int mail_var_path_changed;

/*
 * Print appropriate message(s) if mail has arrived.
 * If mail_var_path_changed is set,
 * then the value of MAIL has mail_var_path_changed,
 * so we just update the values.
 */
static void
chkmail(void)
{
	const char *mpath;
	char *p;
	char *q;
	time_t *mtp;
	struct stackmark smark;
	struct stat statb;

	setstackmark(&smark);
	mpath = mpathset() ? mpathval() : mailval();
	for (mtp = mailtime; mtp < mailtime + MAXMBOXES; mtp++) {
		p = padvance(&mpath, nullstr);
		if (p == NULL)
			break;
		if (*p == '\0')
			continue;
		for (q = p; *q; q++);
#if DEBUG
		if (q[-1] != '/')
			abort();
#endif
		q[-1] = '\0';                   /* delete trailing '/' */
		if (stat(p, &statb) < 0) {
			*mtp = 0;
			continue;
		}
		if (!mail_var_path_changed && statb.st_mtime != *mtp) {
			fprintf(
				stderr, snlfmt,
				pathopt ? pathopt : "you have mail"
			);
		}
		*mtp = statb.st_mtime;
	}
	mail_var_path_changed = 0;
	popstackmark(&smark);
}

static void
changemail(const char *val)
{
	mail_var_path_changed++;
}

#endif /* ASH_MAIL */


/* ============ ??? */

/*
 * Set the shell parameters.
 */
static void
setparam(char **argv)
{
	char **newparam;
	char **ap;
	int nparam;

	for (nparam = 0; argv[nparam]; nparam++);
	ap = newparam = ckmalloc((nparam + 1) * sizeof(*ap));
	while (*argv) {
		*ap++ = ckstrdup(*argv++);
	}
	*ap = NULL;
	freeparam(&shellparam);
	shellparam.malloc = 1;
	shellparam.nparam = nparam;
	shellparam.p = newparam;
#if ENABLE_ASH_GETOPTS
	shellparam.optind = 1;
	shellparam.optoff = -1;
#endif
}

/*
 * Process shell options.  The global variable argptr contains a pointer
 * to the argument list; we advance it past the options.
 */
static void
minus_o(char *name, int val)
{
	int i;

	if (name) {
		for (i = 0; i < NOPTS; i++) {
			if (strcmp(name, optnames(i)) == 0) {
				optlist[i] = val;
				return;
			}
		}
		ash_msg_and_raise_error("illegal option -o %s", name);
	}
	out1str("Current option settings\n");
	for (i = 0; i < NOPTS; i++)
		out1fmt("%-16s%s\n", optnames(i),
				optlist[i] ? "on" : "off");
}
static void
setoption(int flag, int val)
{
	int i;

	for (i = 0; i < NOPTS; i++) {
		if (optletters(i) == flag) {
			optlist[i] = val;
			return;
		}
	}
	ash_msg_and_raise_error("illegal option -%c", flag);
	/* NOTREACHED */
}
static void
options(int cmdline)
{
	char *p;
	int val;
	int c;

	if (cmdline)
		minusc = NULL;
	while ((p = *argptr) != NULL) {
		argptr++;
		c = *p++;
		if (c == '-') {
			val = 1;
			if (p[0] == '\0' || LONE_DASH(p)) {
				if (!cmdline) {
					/* "-" means turn off -x and -v */
					if (p[0] == '\0')
						xflag = vflag = 0;
					/* "--" means reset params */
					else if (*argptr == NULL)
						setparam(argptr);
				}
				break;    /* "-" or  "--" terminates options */
			}
		} else if (c == '+') {
			val = 0;
		} else {
			argptr--;
			break;
		}
		while ((c = *p++) != '\0') {
			if (c == 'c' && cmdline) {
				minusc = p;     /* command is after shell args*/
			} else if (c == 'o') {
				minus_o(*argptr, val);
				if (*argptr)
					argptr++;
			} else if (cmdline && (c == '-')) {     // long options
				if (strcmp(p, "login") == 0)
					isloginsh = 1;
				break;
			} else {
				setoption(c, val);
			}
		}
	}
}

/*
 * The shift builtin command.
 */
static int
shiftcmd(int argc, char **argv)
{
	int n;
	char **ap1, **ap2;

	n = 1;
	if (argc > 1)
		n = number(argv[1]);
	if (n > shellparam.nparam)
		ash_msg_and_raise_error("can't shift that many");
	INT_OFF;
	shellparam.nparam -= n;
	for (ap1 = shellparam.p; --n >= 0; ap1++) {
		if (shellparam.malloc)
			free(*ap1);
	}
	ap2 = shellparam.p;
	while ((*ap2++ = *ap1++) != NULL);
#if ENABLE_ASH_GETOPTS
	shellparam.optind = 1;
	shellparam.optoff = -1;
#endif
	INT_ON;
	return 0;
}

/*
 * POSIX requires that 'set' (but not export or readonly) output the
 * variables in lexicographic order - by the locale's collating order (sigh).
 * Maybe we could keep them in an ordered balanced binary tree
 * instead of hashed lists.
 * For now just roll 'em through qsort for printing...
 */
static int
showvars(const char *sep_prefix, int on, int off)
{
	const char *sep;
	char **ep, **epend;

	ep = listvars(on, off, &epend);
	qsort(ep, epend - ep, sizeof(char *), vpcmp);

	sep = *sep_prefix ? " " : sep_prefix;

	for (; ep < epend; ep++) {
		const char *p;
		const char *q;

		p = strchrnul(*ep, '=');
		q = nullstr;
		if (*p)
			q = single_quote(++p);
		out1fmt("%s%s%.*s%s\n", sep_prefix, sep, (int)(p - *ep), *ep, q);
	}
	return 0;
}

/*
 * The set command builtin.
 */
static int
setcmd(int argc, char **argv)
{
	if (argc == 1)
		return showvars(nullstr, 0, VUNSET);
	INT_OFF;
	options(0);
	optschanged();
	if (*argptr != NULL) {
		setparam(argptr);
	}
	INT_ON;
	return 0;
}

#if ENABLE_ASH_RANDOM_SUPPORT
/* Roughly copied from bash.. */
static void
change_random(const char *value)
{
	if (value == NULL) {
		/* "get", generate */
		char buf[16];

		rseed = rseed * 1103515245 + 12345;
		sprintf(buf, "%d", (unsigned int)((rseed & 32767)));
		/* set without recursion */
		setvar(vrandom.text, buf, VNOFUNC);
		vrandom.flags &= ~VNOFUNC;
	} else {
		/* set/reset */
		rseed = strtoul(value, (char **)NULL, 10);
	}
}
#endif

#if ENABLE_ASH_GETOPTS
static int
getopts(char *optstr, char *optvar, char **optfirst, int *param_optind, int *optoff)
{
	char *p, *q;
	char c = '?';
	int done = 0;
	int err = 0;
	char s[12];
	char **optnext;

	if (*param_optind < 1)
		return 1;
	optnext = optfirst + *param_optind - 1;

	if (*param_optind <= 1 || *optoff < 0 || strlen(optnext[-1]) < *optoff)
		p = NULL;
	else
		p = optnext[-1] + *optoff;
	if (p == NULL || *p == '\0') {
		/* Current word is done, advance */
		p = *optnext;
		if (p == NULL || *p != '-' || *++p == '\0') {
 atend:
			p = NULL;
			done = 1;
			goto out;
		}
		optnext++;
		if (LONE_DASH(p))        /* check for "--" */
			goto atend;
	}

	c = *p++;
	for (q = optstr; *q != c; ) {
		if (*q == '\0') {
			if (optstr[0] == ':') {
				s[0] = c;
				s[1] = '\0';
				err |= setvarsafe("OPTARG", s, 0);
			} else {
				fprintf(stderr, "Illegal option -%c\n", c);
				unsetvar("OPTARG");
			}
			c = '?';
			goto out;
		}
		if (*++q == ':')
			q++;
	}

	if (*++q == ':') {
		if (*p == '\0' && (p = *optnext) == NULL) {
			if (optstr[0] == ':') {
				s[0] = c;
				s[1] = '\0';
				err |= setvarsafe("OPTARG", s, 0);
				c = ':';
			} else {
				fprintf(stderr, "No arg for -%c option\n", c);
				unsetvar("OPTARG");
				c = '?';
			}
			goto out;
		}

		if (p == *optnext)
			optnext++;
		err |= setvarsafe("OPTARG", p, 0);
		p = NULL;
	} else
		err |= setvarsafe("OPTARG", nullstr, 0);
 out:
	*optoff = p ? p - *(optnext - 1) : -1;
	*param_optind = optnext - optfirst + 1;
	fmtstr(s, sizeof(s), "%d", *param_optind);
	err |= setvarsafe("OPTIND", s, VNOFUNC);
	s[0] = c;
	s[1] = '\0';
	err |= setvarsafe(optvar, s, 0);
	if (err) {
		*param_optind = 1;
		*optoff = -1;
		flush_stdout_stderr();
		raise_exception(EXERROR);
	}
	return done;
}

/*
 * The getopts builtin.  Shellparam.optnext points to the next argument
 * to be processed.  Shellparam.optptr points to the next character to
 * be processed in the current argument.  If shellparam.optnext is NULL,
 * then it's the first time getopts has been called.
 */
static int
getoptscmd(int argc, char **argv)
{
	char **optbase;

	if (argc < 3)
		ash_msg_and_raise_error("usage: getopts optstring var [arg]");
	if (argc == 3) {
		optbase = shellparam.p;
		if (shellparam.optind > shellparam.nparam + 1) {
			shellparam.optind = 1;
			shellparam.optoff = -1;
		}
	} else {
		optbase = &argv[3];
		if (shellparam.optind > argc - 2) {
			shellparam.optind = 1;
			shellparam.optoff = -1;
		}
	}

	return getopts(argv[1], argv[2], optbase, &shellparam.optind,
			&shellparam.optoff);
}
#endif /* ASH_GETOPTS */


/* ============ Shell parser */

static int tokpushback;                /* last token pushed back */
#define NEOF ((union node *)&tokpushback)
static int parsebackquote;             /* nonzero if we are inside backquotes */
static int lasttoken;                  /* last token read */
static char *wordtext;                 /* text of last word returned by readtoken */
static struct nodelist *backquotelist;
static union node *redirnode;
static struct heredoc *heredoc;
static int quoteflag;                  /* set if (part of) last token was quoted */

static void raise_error_syntax(const char *) ATTRIBUTE_NORETURN;
static void
raise_error_syntax(const char *msg)
{
	ash_msg_and_raise_error("syntax error: %s", msg);
	/* NOTREACHED */
}

/*
 * Called when an unexpected token is read during the parse.  The argument
 * is the token that is expected, or -1 if more than one type of token can
 * occur at this point.
 */
static void raise_error_unexpected_syntax(int) ATTRIBUTE_NORETURN;
static void
raise_error_unexpected_syntax(int token)
{
	char msg[64];
	int l;

	l = sprintf(msg, "%s unexpected", tokname(lasttoken));
	if (token >= 0)
		sprintf(msg + l, " (expecting %s)", tokname(token));
	raise_error_syntax(msg);
	/* NOTREACHED */
}

#define EOFMARKLEN 79

struct heredoc {
	struct heredoc *next;   /* next here document in list */
	union node *here;               /* redirection node */
	char *eofmark;          /* string indicating end of input */
	int striptabs;          /* if set, strip leading tabs */
};

static struct heredoc *heredoclist;    /* list of here documents to read */

/* parsing is heavily cross-recursive, need these forward decls */
static union node *andor(void);
static union node *pipeline(void);
static union node *parse_command(void);
static void parseheredoc(void);
static char peektoken(void);
static int readtoken(void);

static union node *
list(int nlflag)
{
	union node *n1, *n2, *n3;
	int tok;

	checkkwd = CHKNL | CHKKWD | CHKALIAS;
	if (nlflag == 2 && peektoken())
		return NULL;
	n1 = NULL;
	for (;;) {
		n2 = andor();
		tok = readtoken();
		if (tok == TBACKGND) {
			if (n2->type == NPIPE) {
				n2->npipe.backgnd = 1;
			} else {
				if (n2->type != NREDIR) {
					n3 = stalloc(sizeof(struct nredir));
					n3->nredir.n = n2;
					n3->nredir.redirect = NULL;
					n2 = n3;
				}
				n2->type = NBACKGND;
			}
		}
		if (n1 == NULL) {
			n1 = n2;
		} else {
			n3 = stalloc(sizeof(struct nbinary));
			n3->type = NSEMI;
			n3->nbinary.ch1 = n1;
			n3->nbinary.ch2 = n2;
			n1 = n3;
		}
		switch (tok) {
		case TBACKGND:
		case TSEMI:
			tok = readtoken();
			/* fall through */
		case TNL:
			if (tok == TNL) {
				parseheredoc();
				if (nlflag == 1)
					return n1;
			} else {
				tokpushback++;
			}
			checkkwd = CHKNL | CHKKWD | CHKALIAS;
			if (peektoken())
				return n1;
			break;
		case TEOF:
			if (heredoclist)
				parseheredoc();
			else
				pungetc();              /* push back EOF on input */
			return n1;
		default:
			if (nlflag == 1)
				raise_error_unexpected_syntax(-1);
			tokpushback++;
			return n1;
		}
	}
}

static union node *
andor(void)
{
	union node *n1, *n2, *n3;
	int t;

	n1 = pipeline();
	for (;;) {
		t = readtoken();
		if (t == TAND) {
			t = NAND;
		} else if (t == TOR) {
			t = NOR;
		} else {
			tokpushback++;
			return n1;
		}
		checkkwd = CHKNL | CHKKWD | CHKALIAS;
		n2 = pipeline();
		n3 = stalloc(sizeof(struct nbinary));
		n3->type = t;
		n3->nbinary.ch1 = n1;
		n3->nbinary.ch2 = n2;
		n1 = n3;
	}
}

static union node *
pipeline(void)
{
	union node *n1, *n2, *pipenode;
	struct nodelist *lp, *prev;
	int negate;

	negate = 0;
	TRACE(("pipeline: entered\n"));
	if (readtoken() == TNOT) {
		negate = !negate;
		checkkwd = CHKKWD | CHKALIAS;
	} else
		tokpushback++;
	n1 = parse_command();
	if (readtoken() == TPIPE) {
		pipenode = stalloc(sizeof(struct npipe));
		pipenode->type = NPIPE;
		pipenode->npipe.backgnd = 0;
		lp = stalloc(sizeof(struct nodelist));
		pipenode->npipe.cmdlist = lp;
		lp->n = n1;
		do {
			prev = lp;
			lp = stalloc(sizeof(struct nodelist));
			checkkwd = CHKNL | CHKKWD | CHKALIAS;
			lp->n = parse_command();
			prev->next = lp;
		} while (readtoken() == TPIPE);
		lp->next = NULL;
		n1 = pipenode;
	}
	tokpushback++;
	if (negate) {
		n2 = stalloc(sizeof(struct nnot));
		n2->type = NNOT;
		n2->nnot.com = n1;
		return n2;
	}
	return n1;
}

static union node *
makename(void)
{
	union node *n;

	n = stalloc(sizeof(struct narg));
	n->type = NARG;
	n->narg.next = NULL;
	n->narg.text = wordtext;
	n->narg.backquote = backquotelist;
	return n;
}

static void
fixredir(union node *n, const char *text, int err)
{
	TRACE(("Fix redir %s %d\n", text, err));
	if (!err)
		n->ndup.vname = NULL;

	if (isdigit(text[0]) && text[1] == '\0')
		n->ndup.dupfd = text[0] - '0';
	else if (LONE_DASH(text))
		n->ndup.dupfd = -1;
	else {
		if (err)
			raise_error_syntax("Bad fd number");
		n->ndup.vname = makename();
	}
}

/*
 * Returns true if the text contains nothing to expand (no dollar signs
 * or backquotes).
 */
static int
noexpand(char *text)
{
	char *p;
	char c;

	p = text;
	while ((c = *p++) != '\0') {
		if (c == CTLQUOTEMARK)
			continue;
		if (c == CTLESC)
			p++;
		else if (SIT(c, BASESYNTAX) == CCTL)
			return 0;
	}
	return 1;
}

static void
parsefname(void)
{
	union node *n = redirnode;

	if (readtoken() != TWORD)
		raise_error_unexpected_syntax(-1);
	if (n->type == NHERE) {
		struct heredoc *here = heredoc;
		struct heredoc *p;
		int i;

		if (quoteflag == 0)
			n->type = NXHERE;
		TRACE(("Here document %d\n", n->type));
		if (!noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN)
			raise_error_syntax("Illegal eof marker for << redirection");
		rmescapes(wordtext);
		here->eofmark = wordtext;
		here->next = NULL;
		if (heredoclist == NULL)
			heredoclist = here;
		else {
			for (p = heredoclist; p->next; p = p->next);
			p->next = here;
		}
	} else if (n->type == NTOFD || n->type == NFROMFD) {
		fixredir(n, wordtext, 0);
	} else {
		n->nfile.fname = makename();
	}
}

static union node *
simplecmd(void)
{
	union node *args, **app;
	union node *n = NULL;
	union node *vars, **vpp;
	union node **rpp, *redir;
	int savecheckkwd;

	args = NULL;
	app = &args;
	vars = NULL;
	vpp = &vars;
	redir = NULL;
	rpp = &redir;

	savecheckkwd = CHKALIAS;
	for (;;) {
		checkkwd = savecheckkwd;
		switch (readtoken()) {
		case TWORD:
			n = stalloc(sizeof(struct narg));
			n->type = NARG;
			n->narg.text = wordtext;
			n->narg.backquote = backquotelist;
			if (savecheckkwd && isassignment(wordtext)) {
				*vpp = n;
				vpp = &n->narg.next;
			} else {
				*app = n;
				app = &n->narg.next;
				savecheckkwd = 0;
			}
			break;
		case TREDIR:
			*rpp = n = redirnode;
			rpp = &n->nfile.next;
			parsefname();   /* read name of redirection file */
			break;
		case TLP:
			if (args && app == &args->narg.next
			 && !vars && !redir
			) {
				struct builtincmd *bcmd;
				const char *name;

				/* We have a function */
				if (readtoken() != TRP)
					raise_error_unexpected_syntax(TRP);
				name = n->narg.text;
				if (!goodname(name)
				 || ((bcmd = find_builtin(name)) && IS_BUILTIN_SPECIAL(bcmd))
				) {
					raise_error_syntax("Bad function name");
				}
				n->type = NDEFUN;
				checkkwd = CHKNL | CHKKWD | CHKALIAS;
				n->narg.next = parse_command();
				return n;
			}
			/* fall through */
		default:
			tokpushback++;
			goto out;
		}
	}
 out:
	*app = NULL;
	*vpp = NULL;
	*rpp = NULL;
	n = stalloc(sizeof(struct ncmd));
	n->type = NCMD;
	n->ncmd.args = args;
	n->ncmd.assign = vars;
	n->ncmd.redirect = redir;
	return n;
}

static union node *
parse_command(void)
{
	union node *n1, *n2;
	union node *ap, **app;
	union node *cp, **cpp;
	union node *redir, **rpp;
	union node **rpp2;
	int t;

	redir = NULL;
	rpp2 = &redir;

	switch (readtoken()) {
	default:
		raise_error_unexpected_syntax(-1);
		/* NOTREACHED */
	case TIF:
		n1 = stalloc(sizeof(struct nif));
		n1->type = NIF;
		n1->nif.test = list(0);
		if (readtoken() != TTHEN)
			raise_error_unexpected_syntax(TTHEN);
		n1->nif.ifpart = list(0);
		n2 = n1;
		while (readtoken() == TELIF) {
			n2->nif.elsepart = stalloc(sizeof(struct nif));
			n2 = n2->nif.elsepart;
			n2->type = NIF;
			n2->nif.test = list(0);
			if (readtoken() != TTHEN)
				raise_error_unexpected_syntax(TTHEN);
			n2->nif.ifpart = list(0);
		}
		if (lasttoken == TELSE)
			n2->nif.elsepart = list(0);
		else {
			n2->nif.elsepart = NULL;
			tokpushback++;
		}
		t = TFI;
		break;
	case TWHILE:
	case TUNTIL: {
		int got;
		n1 = stalloc(sizeof(struct nbinary));
		n1->type = (lasttoken == TWHILE) ? NWHILE : NUNTIL;
		n1->nbinary.ch1 = list(0);
		got = readtoken();
		if (got != TDO) {
			TRACE(("expecting DO got %s %s\n", tokname(got),
					got == TWORD ? wordtext : ""));
			raise_error_unexpected_syntax(TDO);
		}
		n1->nbinary.ch2 = list(0);
		t = TDONE;
		break;
	}
	case TFOR:
		if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
			raise_error_syntax("Bad for loop variable");
		n1 = stalloc(sizeof(struct nfor));
		n1->type = NFOR;
		n1->nfor.var = wordtext;
		checkkwd = CHKKWD | CHKALIAS;
		if (readtoken() == TIN) {
			app = &ap;
			while (readtoken() == TWORD) {
				n2 = stalloc(sizeof(struct narg));
				n2->type = NARG;
				n2->narg.text = wordtext;
				n2->narg.backquote = backquotelist;
				*app = n2;
				app = &n2->narg.next;
			}
			*app = NULL;
			n1->nfor.args = ap;
			if (lasttoken != TNL && lasttoken != TSEMI)
				raise_error_unexpected_syntax(-1);
		} else {
			n2 = stalloc(sizeof(struct narg));
			n2->type = NARG;
			n2->narg.text = (char *)dolatstr;
			n2->narg.backquote = NULL;
			n2->narg.next = NULL;
			n1->nfor.args = n2;
			/*
			 * Newline or semicolon here is optional (but note
			 * that the original Bourne shell only allowed NL).
			 */
			if (lasttoken != TNL && lasttoken != TSEMI)
				tokpushback++;
		}
		checkkwd = CHKNL | CHKKWD | CHKALIAS;
		if (readtoken() != TDO)
			raise_error_unexpected_syntax(TDO);
		n1->nfor.body = list(0);
		t = TDONE;
		break;
	case TCASE:
		n1 = stalloc(sizeof(struct ncase));
		n1->type = NCASE;
		if (readtoken() != TWORD)
			raise_error_unexpected_syntax(TWORD);
		n1->ncase.expr = n2 = stalloc(sizeof(struct narg));
		n2->type = NARG;
		n2->narg.text = wordtext;
		n2->narg.backquote = backquotelist;
		n2->narg.next = NULL;
		do {
			checkkwd = CHKKWD | CHKALIAS;
		} while (readtoken() == TNL);
		if (lasttoken != TIN)
			raise_error_unexpected_syntax(TIN);
		cpp = &n1->ncase.cases;
 next_case:
		checkkwd = CHKNL | CHKKWD;
		t = readtoken();
		while (t != TESAC) {
			if (lasttoken == TLP)
				readtoken();
			*cpp = cp = stalloc(sizeof(struct nclist));
			cp->type = NCLIST;
			app = &cp->nclist.pattern;
			for (;;) {
				*app = ap = stalloc(sizeof(struct narg));
				ap->type = NARG;
				ap->narg.text = wordtext;
				ap->narg.backquote = backquotelist;
				if (readtoken() != TPIPE)
					break;
				app = &ap->narg.next;
				readtoken();
			}
			ap->narg.next = NULL;
			if (lasttoken != TRP)
				raise_error_unexpected_syntax(TRP);
			cp->nclist.body = list(2);

			cpp = &cp->nclist.next;

			checkkwd = CHKNL | CHKKWD;
			t = readtoken();
			if (t != TESAC) {
				if (t != TENDCASE)
					raise_error_unexpected_syntax(TENDCASE);
				goto next_case;
			}
		}
		*cpp = NULL;
		goto redir;
	case TLP:
		n1 = stalloc(sizeof(struct nredir));
		n1->type = NSUBSHELL;
		n1->nredir.n = list(0);
		n1->nredir.redirect = NULL;
		t = TRP;
		break;
	case TBEGIN:
		n1 = list(0);
		t = TEND;
		break;
	case TWORD:
	case TREDIR:
		tokpushback++;
		return simplecmd();
	}

	if (readtoken() != t)
		raise_error_unexpected_syntax(t);

 redir:
	/* Now check for redirection which may follow command */
	checkkwd = CHKKWD | CHKALIAS;
	rpp = rpp2;
	while (readtoken() == TREDIR) {
		*rpp = n2 = redirnode;
		rpp = &n2->nfile.next;
		parsefname();
	}
	tokpushback++;
	*rpp = NULL;
	if (redir) {
		if (n1->type != NSUBSHELL) {
			n2 = stalloc(sizeof(struct nredir));
			n2->type = NREDIR;
			n2->nredir.n = n1;
			n1 = n2;
		}
		n1->nredir.redirect = redir;
	}
	return n1;
}

/*
 * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
 * is not NULL, read a here document.  In the latter case, eofmark is the
 * word which marks the end of the document and striptabs is true if
 * leading tabs should be stripped from the document.  The argument firstc
 * is the first character of the input token or document.
 *
 * Because C does not have internal subroutines, I have simulated them
 * using goto's to implement the subroutine linkage.  The following macros
 * will run code that appears at the end of readtoken1.
 */

static int parsebackquote;             /* nonzero if we are inside backquotes */

#define CHECKEND()      {goto checkend; checkend_return:;}
#define PARSEREDIR()    {goto parseredir; parseredir_return:;}
#define PARSESUB()      {goto parsesub; parsesub_return:;}
#define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;}
#define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;}
#define PARSEARITH()    {goto parsearith; parsearith_return:;}

static int
readtoken1(int firstc, int syntax, char *eofmark, int striptabs)
{
	int c = firstc;
	char *out;
	int len;
	char line[EOFMARKLEN + 1];
	struct nodelist *bqlist = 0;
	int quotef = 0;
	int dblquote = 0;
	int varnest = 0;    /* levels of variables expansion */
	int arinest = 0;    /* levels of arithmetic expansion */
	int parenlevel = 0; /* levels of parens in arithmetic */
	int dqvarnest = 0;  /* levels of variables expansion within double quotes */
	int oldstyle = 0;
	int prevsyntax = 0; /* syntax before arithmetic */
#if __GNUC__
	/* Avoid longjmp clobbering */
	(void) &out;
	(void) &quotef;
	(void) &dblquote;
	(void) &varnest;
	(void) &arinest;
	(void) &parenlevel;
	(void) &dqvarnest;
	(void) &oldstyle;
	(void) &prevsyntax;
	(void) &syntax;
#endif

	startlinno = plinno;
	dblquote = 0;
	if (syntax == DQSYNTAX)
		dblquote = 1;
	quotef = 0;
	bqlist = NULL;
	varnest = 0;
	arinest = 0;
	parenlevel = 0;
	dqvarnest = 0;

	STARTSTACKSTR(out);
	loop: { /* for each line, until end of word */
		CHECKEND();     /* set c to PEOF if at end of here document */
		for (;;) {      /* until end of line or end of word */
			CHECKSTRSPACE(4, out);  /* permit 4 calls to USTPUTC */
			switch (SIT(c, syntax)) {
			case CNL:       /* '\n' */
				if (syntax == BASESYNTAX)
					goto endword;   /* exit outer loop */
				USTPUTC(c, out);
				plinno++;
				if (doprompt)
					setprompt(2);
				c = pgetc();
				goto loop;              /* continue outer loop */
			case CWORD:
				USTPUTC(c, out);
				break;
			case CCTL:
				if (eofmark == NULL || dblquote)
					USTPUTC(CTLESC, out);
				USTPUTC(c, out);
				break;
			case CBACK:     /* backslash */
				c = pgetc2();
				if (c == PEOF) {
					USTPUTC(CTLESC, out);
					USTPUTC('\\', out);
					pungetc();
				} else if (c == '\n') {
					if (doprompt)
						setprompt(2);
				} else {
					if (dblquote &&
						c != '\\' && c != '`' &&
						c != '$' && (
							c != '"' ||
							eofmark != NULL)
					) {
						USTPUTC(CTLESC, out);
						USTPUTC('\\', out);
					}
					if (SIT(c, SQSYNTAX) == CCTL)
						USTPUTC(CTLESC, out);
					USTPUTC(c, out);
					quotef++;
				}
				break;
			case CSQUOTE:
				syntax = SQSYNTAX;
 quotemark:
				if (eofmark == NULL) {
					USTPUTC(CTLQUOTEMARK, out);
				}
				break;
			case CDQUOTE:
				syntax = DQSYNTAX;
				dblquote = 1;
				goto quotemark;
			case CENDQUOTE:
				if (eofmark != NULL && arinest == 0
				 && varnest == 0
				) {
					USTPUTC(c, out);
				} else {
					if (dqvarnest == 0) {
						syntax = BASESYNTAX;
						dblquote = 0;
					}
					quotef++;
					goto quotemark;
				}
				break;
			case CVAR:      /* '$' */
				PARSESUB();             /* parse substitution */
				break;
			case CENDVAR:   /* '}' */
				if (varnest > 0) {
					varnest--;
					if (dqvarnest > 0) {
						dqvarnest--;
					}
					USTPUTC(CTLENDVAR, out);
				} else {
					USTPUTC(c, out);
				}
				break;
#if ENABLE_ASH_MATH_SUPPORT
			case CLP:       /* '(' in arithmetic */
				parenlevel++;
				USTPUTC(c, out);
				break;
			case CRP:       /* ')' in arithmetic */
				if (parenlevel > 0) {
					USTPUTC(c, out);
					--parenlevel;
				} else {
					if (pgetc() == ')') {
						if (--arinest == 0) {
							USTPUTC(CTLENDARI, out);
							syntax = prevsyntax;
							if (syntax == DQSYNTAX)
								dblquote = 1;
							else
								dblquote = 0;
						} else
							USTPUTC(')', out);
					} else {
						/*
						 * unbalanced parens
						 *  (don't 2nd guess - no error)
						 */
						pungetc();
						USTPUTC(')', out);
					}
				}
				break;
#endif
			case CBQUOTE:   /* '`' */
				PARSEBACKQOLD();
				break;
			case CENDFILE:
				goto endword;           /* exit outer loop */
			case CIGN:
				break;
			default:
				if (varnest == 0)
					goto endword;   /* exit outer loop */
#if ENABLE_ASH_ALIAS
				if (c != PEOA)
#endif
					USTPUTC(c, out);

			}
			c = pgetc_macro();
		}
	}
 endword:
#if ENABLE_ASH_MATH_SUPPORT
	if (syntax == ARISYNTAX)
		raise_error_syntax("Missing '))'");
#endif
	if (syntax != BASESYNTAX && !parsebackquote && eofmark == NULL)
		raise_error_syntax("Unterminated quoted string");
	if (varnest != 0) {
		startlinno = plinno;
		/* { */
		raise_error_syntax("Missing '}'");
	}
	USTPUTC('\0', out);
	len = out - (char *)stackblock();
	out = stackblock();
	if (eofmark == NULL) {
		if ((c == '>' || c == '<')
		 && quotef == 0
		 && len <= 2
		 && (*out == '\0' || isdigit(*out))) {
			PARSEREDIR();
			return lasttoken = TREDIR;
		} else {
			pungetc();
		}
	}
	quoteflag = quotef;
	backquotelist = bqlist;
	grabstackblock(len);
	wordtext = out;
	lasttoken = TWORD;
	return lasttoken;
/* end of readtoken routine */

/*
 * Check to see whether we are at the end of the here document.  When this
 * is called, c is set to the first character of the next input line.  If
 * we are at the end of the here document, this routine sets the c to PEOF.
 */
checkend: {
	if (eofmark) {
#if ENABLE_ASH_ALIAS
		if (c == PEOA) {
			c = pgetc2();
		}
#endif
		if (striptabs) {
			while (c == '\t') {
				c = pgetc2();
			}
		}
		if (c == *eofmark) {
			if (pfgets(line, sizeof(line)) != NULL) {
				char *p, *q;

				p = line;
				for (q = eofmark + 1; *q && *p == *q; p++, q++);
				if (*p == '\n' && *q == '\0') {
					c = PEOF;
					plinno++;
					needprompt = doprompt;
				} else {
					pushstring(line, NULL);
				}
			}
		}
	}
	goto checkend_return;
}

/*
 * Parse a redirection operator.  The variable "out" points to a string
 * specifying the fd to be redirected.  The variable "c" contains the
 * first character of the redirection operator.
 */
parseredir: {
	char fd = *out;
	union node *np;

	np = stalloc(sizeof(struct nfile));
	if (c == '>') {
		np->nfile.fd = 1;
		c = pgetc();
		if (c == '>')
			np->type = NAPPEND;
		else if (c == '|')
			np->type = NCLOBBER;
		else if (c == '&')
			np->type = NTOFD;
		else {
			np->type = NTO;
			pungetc();
		}
	} else {        /* c == '<' */
		np->nfile.fd = 0;
		c = pgetc();
		switch (c) {
		case '<':
			if (sizeof(struct nfile) != sizeof(struct nhere)) {
				np = stalloc(sizeof(struct nhere));
				np->nfile.fd = 0;
			}
			np->type = NHERE;
			heredoc = stalloc(sizeof(struct heredoc));
			heredoc->here = np;
			c = pgetc();
			if (c == '-') {
				heredoc->striptabs = 1;
			} else {
				heredoc->striptabs = 0;
				pungetc();
			}
			break;

		case '&':
			np->type = NFROMFD;
			break;

		case '>':
			np->type = NFROMTO;
			break;

		default:
			np->type = NFROM;
			pungetc();
			break;
		}
	}
	if (fd != '\0')
		np->nfile.fd = fd - '0';
	redirnode = np;
	goto parseredir_return;
}

/*
 * Parse a substitution.  At this point, we have read the dollar sign
 * and nothing else.
 */

/* is_special(c) evaluates to 1 for c in "!#$*-0123456789?@"; 0 otherwise
 * (assuming ascii char codes, as the original implementation did) */
#define is_special(c) \
	((((unsigned int)c) - 33 < 32) \
			&& ((0xc1ff920dUL >> (((unsigned int)c) - 33)) & 1))
parsesub: {
	int subtype;
	int typeloc;
	int flags;
	char *p;
	static const char types[] = "}-+?=";

	c = pgetc();
	if (
		c <= PEOA_OR_PEOF  ||
		(c != '(' && c != '{' && !is_name(c) && !is_special(c))
	) {
		USTPUTC('$', out);
		pungetc();
	} else if (c == '(') {  /* $(command) or $((arith)) */
		if (pgetc() == '(') {
#if ENABLE_ASH_MATH_SUPPORT
			PARSEARITH();
#else
			raise_error_syntax("We unsupport $((arith))");
#endif
		} else {
			pungetc();
			PARSEBACKQNEW();
		}
	} else {
		USTPUTC(CTLVAR, out);
		typeloc = out - (char *)stackblock();
		USTPUTC(VSNORMAL, out);
		subtype = VSNORMAL;
		if (c == '{') {
			c = pgetc();
			if (c == '#') {
				c = pgetc();
				if (c == '}')
					c = '#';
				else
					subtype = VSLENGTH;
			} else
				subtype = 0;
		}
		if (c > PEOA_OR_PEOF && is_name(c)) {
			do {
				STPUTC(c, out);
				c = pgetc();
			} while (c > PEOA_OR_PEOF && is_in_name(c));
		} else if (isdigit(c)) {
			do {
				STPUTC(c, out);
				c = pgetc();
			} while (isdigit(c));
		} else if (is_special(c)) {
			USTPUTC(c, out);
			c = pgetc();
		} else
 badsub:		raise_error_syntax("Bad substitution");

		STPUTC('=', out);
		flags = 0;
		if (subtype == 0) {
			switch (c) {
			case ':':
				flags = VSNUL;
				c = pgetc();
				/*FALLTHROUGH*/
			default:
				p = strchr(types, c);
				if (p == NULL)
					goto badsub;
				subtype = p - types + VSNORMAL;
				break;
			case '%':
			case '#':
				{
					int cc = c;
					subtype = c == '#' ? VSTRIMLEFT :
					                     VSTRIMRIGHT;
					c = pgetc();
					if (c == cc)
						subtype++;
					else
						pungetc();
					break;
				}
			}
		} else {
			pungetc();
		}
		if (dblquote || arinest)
			flags |= VSQUOTE;
		*((char *)stackblock() + typeloc) = subtype | flags;
		if (subtype != VSNORMAL) {
			varnest++;
			if (dblquote || arinest) {
				dqvarnest++;
			}
		}
	}
	goto parsesub_return;
}

/*
 * Called to parse command substitutions.  Newstyle is set if the command
 * is enclosed inside $(...); nlpp is a pointer to the head of the linked
 * list of commands (passed by reference), and savelen is the number of
 * characters on the top of the stack which must be preserved.
 */
parsebackq: {
	struct nodelist **nlpp;
	int savepbq;
	union node *n;
	char *volatile str;
	struct jmploc jmploc;
	struct jmploc *volatile savehandler;
	size_t savelen;
	int saveprompt = 0;
#ifdef __GNUC__
	(void) &saveprompt;
#endif

	savepbq = parsebackquote;
	if (setjmp(jmploc.loc)) {
		if (str)
			free(str);
		parsebackquote = 0;
		exception_handler = savehandler;
		longjmp(exception_handler->loc, 1);
	}
	INT_OFF;
	str = NULL;
	savelen = out - (char *)stackblock();
	if (savelen > 0) {
		str = ckmalloc(savelen);
		memcpy(str, stackblock(), savelen);
	}
	savehandler = exception_handler;
	exception_handler = &jmploc;
	INT_ON;
	if (oldstyle) {
		/* We must read until the closing backquote, giving special
		   treatment to some slashes, and then push the string and
		   reread it as input, interpreting it normally.  */
		char *pout;
		int pc;
		size_t psavelen;
		char *pstr;


		STARTSTACKSTR(pout);
		for (;;) {
			if (needprompt) {
				setprompt(2);
			}
			pc = pgetc();
			switch (pc) {
			case '`':
				goto done;

			case '\\':
				pc = pgetc();
				if (pc == '\n') {
					plinno++;
					if (doprompt)
						setprompt(2);
					/*
					 * If eating a newline, avoid putting
					 * the newline into the new character
					 * stream (via the STPUTC after the
					 * switch).
					 */
					continue;
				}
				if (pc != '\\' && pc != '`' && pc != '$'
				 && (!dblquote || pc != '"'))
					STPUTC('\\', pout);
				if (pc > PEOA_OR_PEOF) {
					break;
				}
				/* fall through */

			case PEOF:
#if ENABLE_ASH_ALIAS
			case PEOA:
#endif
				startlinno = plinno;
				raise_error_syntax("EOF in backquote substitution");

			case '\n':
				plinno++;
				needprompt = doprompt;
				break;

			default:
				break;
			}
			STPUTC(pc, pout);
		}
 done:
		STPUTC('\0', pout);
		psavelen = pout - (char *)stackblock();
		if (psavelen > 0) {
			pstr = grabstackstr(pout);
			setinputstring(pstr);
		}
	}
	nlpp = &bqlist;
	while (*nlpp)
		nlpp = &(*nlpp)->next;
	*nlpp = stalloc(sizeof(**nlpp));
	(*nlpp)->next = NULL;
	parsebackquote = oldstyle;

	if (oldstyle) {
		saveprompt = doprompt;
		doprompt = 0;
	}

	n = list(2);

	if (oldstyle)
		doprompt = saveprompt;
	else if (readtoken() != TRP)
		raise_error_unexpected_syntax(TRP);

	(*nlpp)->n = n;
	if (oldstyle) {
		/*
		 * Start reading from old file again, ignoring any pushed back
		 * tokens left from the backquote parsing
		 */
		popfile();
		tokpushback = 0;
	}
	while (stackblocksize() <= savelen)
		growstackblock();
	STARTSTACKSTR(out);
	if (str) {
		memcpy(out, str, savelen);
		STADJUST(savelen, out);
		INT_OFF;
		free(str);
		str = NULL;
		INT_ON;
	}
	parsebackquote = savepbq;
	exception_handler = savehandler;
	if (arinest || dblquote)
		USTPUTC(CTLBACKQ | CTLQUOTE, out);
	else
		USTPUTC(CTLBACKQ, out);
	if (oldstyle)
		goto parsebackq_oldreturn;
	goto parsebackq_newreturn;
}

#if ENABLE_ASH_MATH_SUPPORT
/*
 * Parse an arithmetic expansion (indicate start of one and set state)
 */
parsearith: {
	if (++arinest == 1) {
		prevsyntax = syntax;
		syntax = ARISYNTAX;
		USTPUTC(CTLARI, out);
		if (dblquote)
			USTPUTC('"', out);
		else
			USTPUTC(' ', out);
	} else {
		/*
		 * we collapse embedded arithmetic expansion to
		 * parenthesis, which should be equivalent
		 */
		USTPUTC('(', out);
	}
	goto parsearith_return;
}
#endif

} /* end of readtoken */

/*
 * Read the next input token.
 * If the token is a word, we set backquotelist to the list of cmds in
 *      backquotes.  We set quoteflag to true if any part of the word was
 *      quoted.
 * If the token is TREDIR, then we set redirnode to a structure containing
 *      the redirection.
 * In all cases, the variable startlinno is set to the number of the line
 *      on which the token starts.
 *
 * [Change comment:  here documents and internal procedures]
 * [Readtoken shouldn't have any arguments.  Perhaps we should make the
 *  word parsing code into a separate routine.  In this case, readtoken
 *  doesn't need to have any internal procedures, but parseword does.
 *  We could also make parseoperator in essence the main routine, and
 *  have parseword (readtoken1?) handle both words and redirection.]
 */
#define NEW_xxreadtoken
#ifdef NEW_xxreadtoken
/* singles must be first! */
static const char xxreadtoken_chars[7] = { '\n', '(', ')', '&', '|', ';', 0 };

static const char xxreadtoken_tokens[] = {
	TNL, TLP, TRP,          /* only single occurrence allowed */
	TBACKGND, TPIPE, TSEMI, /* if single occurrence */
	TEOF,                   /* corresponds to trailing nul */
	TAND, TOR, TENDCASE,    /* if double occurrence */
};

#define xxreadtoken_doubles \
	(sizeof(xxreadtoken_tokens) - sizeof(xxreadtoken_chars))
#define xxreadtoken_singles \
	(sizeof(xxreadtoken_chars) - xxreadtoken_doubles - 1)

static int
xxreadtoken(void)
{
	int c;

	if (tokpushback) {
		tokpushback = 0;
		return lasttoken;
	}
	if (needprompt) {
		setprompt(2);
	}
	startlinno = plinno;
	for (;;) {                      /* until token or start of word found */
		c = pgetc_macro();

		if ((c != ' ') && (c != '\t')
#if ENABLE_ASH_ALIAS
		 && (c != PEOA)
#endif
		) {
			if (c == '#') {
				while ((c = pgetc()) != '\n' && c != PEOF);
				pungetc();
			} else if (c == '\\') {
				if (pgetc() != '\n') {
					pungetc();
					goto READTOKEN1;
				}
				startlinno = ++plinno;
				if (doprompt)
					setprompt(2);
			} else {
				const char *p
					= xxreadtoken_chars + sizeof(xxreadtoken_chars) - 1;

				if (c != PEOF) {
					if (c == '\n') {
						plinno++;
						needprompt = doprompt;
					}

					p = strchr(xxreadtoken_chars, c);
					if (p == NULL) {
 READTOKEN1:
						return readtoken1(c, BASESYNTAX, (char *) NULL, 0);
					}

					if (p - xxreadtoken_chars >= xxreadtoken_singles) {
						if (pgetc() == *p) {    /* double occurrence? */
							p += xxreadtoken_doubles + 1;
						} else {
							pungetc();
						}
					}
				}
				return lasttoken = xxreadtoken_tokens[p - xxreadtoken_chars];
			}
		}
	} /* for */
}
#else
#define RETURN(token)   return lasttoken = token
static int
xxreadtoken(void)
{
	int c;

	if (tokpushback) {
		tokpushback = 0;
		return lasttoken;
	}
	if (needprompt) {
		setprompt(2);
	}
	startlinno = plinno;
	for (;;) {      /* until token or start of word found */
		c = pgetc_macro();
		switch (c) {
		case ' ': case '\t':
#if ENABLE_ASH_ALIAS
		case PEOA:
#endif
			continue;
		case '#':
			while ((c = pgetc()) != '\n' && c != PEOF);
			pungetc();
			continue;
		case '\\':
			if (pgetc() == '\n') {
				startlinno = ++plinno;
				if (doprompt)
					setprompt(2);
				continue;
			}
			pungetc();
			goto breakloop;
		case '\n':
			plinno++;
			needprompt = doprompt;
			RETURN(TNL);
		case PEOF:
			RETURN(TEOF);
		case '&':
			if (pgetc() == '&')
				RETURN(TAND);
			pungetc();
			RETURN(TBACKGND);
		case '|':
			if (pgetc() == '|')
				RETURN(TOR);
			pungetc();
			RETURN(TPIPE);
		case ';':
			if (pgetc() == ';')
				RETURN(TENDCASE);
			pungetc();
			RETURN(TSEMI);
		case '(':
			RETURN(TLP);
		case ')':
			RETURN(TRP);
		default:
			goto breakloop;
		}
	}
 breakloop:
	return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
#undef RETURN
}
#endif /* NEW_xxreadtoken */

static int
readtoken(void)
{
	int t;
#if DEBUG
	int alreadyseen = tokpushback;
#endif

#if ENABLE_ASH_ALIAS
 top:
#endif

	t = xxreadtoken();

	/*
	 * eat newlines
	 */
	if (checkkwd & CHKNL) {
		while (t == TNL) {
			parseheredoc();
			t = xxreadtoken();
		}
	}

	if (t != TWORD || quoteflag) {
		goto out;
	}

	/*
	 * check for keywords
	 */
	if (checkkwd & CHKKWD) {
		const char *const *pp;

		pp = findkwd(wordtext);
		if (pp) {
			lasttoken = t = pp - tokname_array;
			TRACE(("keyword %s recognized\n", tokname(t)));
			goto out;
		}
	}

	if (checkkwd & CHKALIAS) {
#if ENABLE_ASH_ALIAS
		struct alias *ap;
		ap = lookupalias(wordtext, 1);
		if (ap != NULL) {
			if (*ap->val) {
				pushstring(ap->val, ap);
			}
			goto top;
		}
#endif
	}
 out:
	checkkwd = 0;
#if DEBUG
	if (!alreadyseen)
		TRACE(("token %s %s\n", tokname(t), t == TWORD ? wordtext : ""));
	else
		TRACE(("reread token %s %s\n", tokname(t), t == TWORD ? wordtext : ""));
#endif
	return t;
}

static char
peektoken(void)
{
	int t;

	t = readtoken();
	tokpushback++;
	return tokname_array[t][0];
}

/*
 * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
 * valid parse tree indicating a blank line.)
 */
static union node *
parsecmd(int interact)
{
	int t;

	tokpushback = 0;
	doprompt = interact;
	if (doprompt)
		setprompt(doprompt);
	needprompt = 0;
	t = readtoken();
	if (t == TEOF)
		return NEOF;
	if (t == TNL)
		return NULL;
	tokpushback++;
	return list(1);
}

/*
 * Input any here documents.
 */
static void
parseheredoc(void)
{
	struct heredoc *here;
	union node *n;

	here = heredoclist;
	heredoclist = 0;

	while (here) {
		if (needprompt) {
			setprompt(2);
		}
		readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
				here->eofmark, here->striptabs);
		n = stalloc(sizeof(struct narg));
		n->narg.type = NARG;
		n->narg.next = NULL;
		n->narg.text = wordtext;
		n->narg.backquote = backquotelist;
		here->here->nhere.doc = n;
		here = here->next;
	}
}


/*
 * called by editline -- any expansions to the prompt should be added here.
 */
#if ENABLE_ASH_EXPAND_PRMT
static const char *
expandstr(const char *ps)
{
	union node n;

	/* XXX Fix (char *) cast. */
	setinputstring((char *)ps);
	readtoken1(pgetc(), DQSYNTAX, nullstr, 0);
	popfile();

	n.narg.type = NARG;
	n.narg.next = NULL;
	n.narg.text = wordtext;
	n.narg.backquote = backquotelist;

	expandarg(&n, NULL, 0);
	return stackblock();
}
#endif

/*
 * Execute a command or commands contained in a string.
 */
static int
evalstring(char *s, int mask)
{
	union node *n;
	struct stackmark smark;
	int skip;

	setinputstring(s);
	setstackmark(&smark);

	skip = 0;
	while ((n = parsecmd(0)) != NEOF) {
		evaltree(n, 0);
		popstackmark(&smark);
		skip = evalskip;
		if (skip)
			break;
	}
	popfile();

	skip &= mask;
	evalskip = skip;
	return skip;
}

/*
 * The eval command.
 */
static int
evalcmd(int argc, char **argv)
{
	char *p;
	char *concat;
	char **ap;

	if (argc > 1) {
		p = argv[1];
		if (argc > 2) {
			STARTSTACKSTR(concat);
			ap = argv + 2;
			for (;;) {
				concat = stack_putstr(p, concat);
				p = *ap++;
				if (p == NULL)
					break;
				STPUTC(' ', concat);
			}
			STPUTC('\0', concat);
			p = grabstackstr(concat);
		}
		evalstring(p, ~SKIPEVAL);

	}
	return exitstatus;
}

/*
 * Read and execute commands.  "Top" is nonzero for the top level command
 * loop; it turns on prompting if the shell is interactive.
 */
static int
cmdloop(int top)
{
	union node *n;
	struct stackmark smark;
	int inter;
	int numeof = 0;

	TRACE(("cmdloop(%d) called\n", top));
	for (;;) {
		int skip;

		setstackmark(&smark);
#if JOBS
		if (jobctl)
			showjobs(stderr, SHOW_CHANGED);
#endif
		inter = 0;
		if (iflag && top) {
			inter++;
#if ENABLE_ASH_MAIL
			chkmail();
#endif
		}
		n = parsecmd(inter);
		/* showtree(n); DEBUG */
		if (n == NEOF) {
			if (!top || numeof >= 50)
				break;
			if (!stoppedjobs()) {
				if (!Iflag)
					break;
				out2str("\nUse \"exit\" to leave shell.\n");
			}
			numeof++;
		} else if (nflag == 0) {
			job_warning = (job_warning == 2) ? 1 : 0;
			numeof = 0;
			evaltree(n, 0);
		}
		popstackmark(&smark);
		skip = evalskip;

		if (skip) {
			evalskip = 0;
			return skip & SKIPEVAL;
		}
	}
	return 0;
}

/*
 * Take commands from a file.  To be compatible we should do a path
 * search for the file, which is necessary to find sub-commands.
 */
static char *
find_dot_file(char *name)
{
	char *fullname;
	const char *path = pathval();
	struct stat statb;

	/* don't try this for absolute or relative paths */
	if (strchr(name, '/'))
		return name;

	while ((fullname = padvance(&path, name)) != NULL) {
		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
			/*
			 * Don't bother freeing here, since it will
			 * be freed by the caller.
			 */
			return fullname;
		}
		stunalloc(fullname);
	}

	/* not found in the PATH */
	ash_msg_and_raise_error("%s: not found", name);
	/* NOTREACHED */
}

static int
dotcmd(int argc, char **argv)
{
	struct strlist *sp;
	volatile struct shparam saveparam;
	int status = 0;

	for (sp = cmdenviron; sp; sp = sp->next)
		setvareq(ckstrdup(sp->text), VSTRFIXED | VTEXTFIXED);

	if (argc >= 2) {        /* That's what SVR2 does */
		char *fullname;

		fullname = find_dot_file(argv[1]);

		if (argc > 2) {
			saveparam = shellparam;
			shellparam.malloc = 0;
			shellparam.nparam = argc - 2;
			shellparam.p = argv + 2;
		};

		setinputfile(fullname, INPUT_PUSH_FILE);
		commandname = fullname;
		cmdloop(0);
		popfile();

		if (argc > 2) {
			freeparam(&shellparam);
			shellparam = saveparam;
		};
		status = exitstatus;
	}
	return status;
}

static int
exitcmd(int argc, char **argv)
{
	if (stoppedjobs())
		return 0;
	if (argc > 1)
		exitstatus = number(argv[1]);
	raise_exception(EXEXIT);
	/* NOTREACHED */
}

#if ENABLE_ASH_BUILTIN_ECHO
static int
echocmd(int argc, char **argv)
{
	return bb_echo(argv);
}
#endif

#if ENABLE_ASH_BUILTIN_TEST
static int
testcmd(int argc, char **argv)
{
	return bb_test(argc, argv);
}
#endif

/*
 * Read a file containing shell functions.
 */
static void
readcmdfile(char *name)
{
	setinputfile(name, INPUT_PUSH_FILE);
	cmdloop(0);
	popfile();
}


/* ============ find_command inplementation */

/*
 * Resolve a command name.  If you change this routine, you may have to
 * change the shellexec routine as well.
 */
static void
find_command(char *name, struct cmdentry *entry, int act, const char *path)
{
	struct tblentry *cmdp;
	int idx;
	int prev;
	char *fullname;
	struct stat statb;
	int e;
	int updatetbl;
	struct builtincmd *bcmd;

	/* If name contains a slash, don't use PATH or hash table */
	if (strchr(name, '/') != NULL) {
		entry->u.index = -1;
		if (act & DO_ABS) {
			while (stat(name, &statb) < 0) {
#ifdef SYSV
				if (errno == EINTR)
					continue;
#endif
				entry->cmdtype = CMDUNKNOWN;
				return;
			}
		}
		entry->cmdtype = CMDNORMAL;
		return;
	}

#if ENABLE_FEATURE_SH_STANDALONE_SHELL
	if (find_applet_by_name(name)) {
		entry->cmdtype = CMDNORMAL;
		entry->u.index = -1;
		return;
	}
	/* Already caught above
	if (is_safe_applet(name)) {
		entry->cmdtype = CMDNORMAL;
		entry->u.index = -1;
		return;
	}*/
#endif

	updatetbl = (path == pathval());
	if (!updatetbl) {
		act |= DO_ALTPATH;
		if (strstr(path, "%builtin") != NULL)
			act |= DO_ALTBLTIN;
	}

	/* If name is in the table, check answer will be ok */
	cmdp = cmdlookup(name, 0);
	if (cmdp != NULL) {
		int bit;

		switch (cmdp->cmdtype) {
		default:
#if DEBUG
			abort();
#endif
		case CMDNORMAL:
			bit = DO_ALTPATH;
			break;
		case CMDFUNCTION:
			bit = DO_NOFUNC;
			break;
		case CMDBUILTIN:
			bit = DO_ALTBLTIN;
			break;
		}
		if (act & bit) {
			updatetbl = 0;
			cmdp = NULL;
		} else if (cmdp->rehash == 0)
			/* if not invalidated by cd, we're done */
			goto success;
	}

	/* If %builtin not in path, check for builtin next */
	bcmd = find_builtin(name);
	if (bcmd) {
		if (IS_BUILTIN_REGULAR(bcmd))
			goto builtin_success;
		if (act & DO_ALTPATH) {
			if (!(act & DO_ALTBLTIN))
				goto builtin_success;
		} else if (builtinloc <= 0) {
			goto builtin_success;
		}
	}

	/* We have to search path. */
	prev = -1;              /* where to start */
	if (cmdp && cmdp->rehash) {     /* doing a rehash */
		if (cmdp->cmdtype == CMDBUILTIN)
			prev = builtinloc;
		else
			prev = cmdp->param.index;
	}

	e = ENOENT;
	idx = -1;
 loop:
	while ((fullname = padvance(&path, name)) != NULL) {
		stunalloc(fullname);
		idx++;
		if (pathopt) {
			if (prefix(pathopt, "builtin")) {
				if (bcmd)
					goto builtin_success;
				continue;
			} else if (!(act & DO_NOFUNC) &&
				   prefix(pathopt, "func")) {
				/* handled below */
			} else {
				/* ignore unimplemented options */
				continue;
			}
		}
		/* if rehash, don't redo absolute path names */
		if (fullname[0] == '/' && idx <= prev) {
			if (idx < prev)
				continue;
			TRACE(("searchexec \"%s\": no change\n", name));
			goto success;
		}
		while (stat(fullname, &statb) < 0) {
#ifdef SYSV
			if (errno == EINTR)
				continue;
#endif
			if (errno != ENOENT && errno != ENOTDIR)
				e = errno;
			goto loop;
		}
		e = EACCES;     /* if we fail, this will be the error */
		if (!S_ISREG(statb.st_mode))
			continue;
		if (pathopt) {          /* this is a %func directory */
			stalloc(strlen(fullname) + 1);
			readcmdfile(fullname);
			cmdp = cmdlookup(name, 0);
			if (cmdp == NULL || cmdp->cmdtype != CMDFUNCTION)
				ash_msg_and_raise_error("%s not defined in %s", name, fullname);
			stunalloc(fullname);
			goto success;
		}
		TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
		if (!updatetbl) {
			entry->cmdtype = CMDNORMAL;
			entry->u.index = idx;
			return;
		}
		INT_OFF;
		cmdp = cmdlookup(name, 1);
		cmdp->cmdtype = CMDNORMAL;
		cmdp->param.index = idx;
		INT_ON;
		goto success;
	}

	/* We failed.  If there was an entry for this command, delete it */
	if (cmdp && updatetbl)
		delete_cmd_entry();
	if (act & DO_ERR)
		ash_msg("%s: %s", name, errmsg(e, "not found"));
	entry->cmdtype = CMDUNKNOWN;
	return;

 builtin_success:
	if (!updatetbl) {
		entry->cmdtype = CMDBUILTIN;
		entry->u.cmd = bcmd;
		return;
	}
	INT_OFF;
	cmdp = cmdlookup(name, 1);
	cmdp->cmdtype = CMDBUILTIN;
	cmdp->param.cmd = bcmd;
	INT_ON;
 success:
	cmdp->rehash = 0;
	entry->cmdtype = cmdp->cmdtype;
	entry->u = cmdp->param;
}


/* ============ trap.c */

/*
 * The trap builtin.
 */
static int
trapcmd(int argc, char **argv)
{
	char *action;
	char **ap;
	int signo;

	nextopt(nullstr);
	ap = argptr;
	if (!*ap) {
		for (signo = 0; signo < NSIG; signo++) {
			if (trap[signo] != NULL) {
				const char *sn;

				sn = get_signame(signo);
				out1fmt("trap -- %s %s\n",
					single_quote(trap[signo]), sn);
			}
		}
		return 0;
	}
	if (!ap[1])
		action = NULL;
	else
		action = *ap++;
	while (*ap) {
		signo = get_signum(*ap);
		if (signo < 0)
			ash_msg_and_raise_error("%s: bad trap", *ap);
		INT_OFF;
		if (action) {
			if (LONE_DASH(action))
				action = NULL;
			else
				action = ckstrdup(action);
		}
		if (trap[signo])
			free(trap[signo]);
		trap[signo] = action;
		if (signo != 0)
			setsignal(signo);
		INT_ON;
		ap++;
	}
	return 0;
}


/* ============ Builtins */

#if !ENABLE_FEATURE_SH_EXTRA_QUIET
/*
 * Lists available builtins
 */
static int
helpcmd(int argc, char **argv)
{
	int col, i;

	out1fmt("\nBuilt-in commands:\n-------------------\n");
	for (col = 0, i = 0; i < NUMBUILTINS; i++) {
		col += out1fmt("%c%s", ((col == 0) ? '\t' : ' '),
					builtintab[i].name + 1);
		if (col > 60) {
			out1fmt("\n");
			col = 0;
		}
	}
#if ENABLE_FEATURE_SH_STANDALONE_SHELL
	for (i = 0; i < NUM_APPLETS; i++) {
		col += out1fmt("%c%s", ((col == 0) ? '\t' : ' '), applets[i].name);
		if (col > 60) {
			out1fmt("\n");
			col = 0;
		}
	}
#endif
	out1fmt("\n\n");
	return EXIT_SUCCESS;
}
#endif /* FEATURE_SH_EXTRA_QUIET */

/*
 * The export and readonly commands.
 */
static int
exportcmd(int argc, char **argv)
{
	struct var *vp;
	char *name;
	const char *p;
	char **aptr;
	int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;

	if (nextopt("p") != 'p') {
		aptr = argptr;
		name = *aptr;
		if (name) {
			do {
				p = strchr(name, '=');
				if (p != NULL) {
					p++;
				} else {
					vp = *findvar(hashvar(name), name);
					if (vp) {
						vp->flags |= flag;
						continue;
					}
				}
				setvar(name, p, flag);
			} while ((name = *++aptr) != NULL);
			return 0;
		}
	}
	showvars(argv[0], flag, 0);
	return 0;
}

/*
 * Delete a function if it exists.
 */
static void
unsetfunc(const char *name)
{
	struct tblentry *cmdp;

	cmdp = cmdlookup(name, 0);
	if (cmdp!= NULL && cmdp->cmdtype == CMDFUNCTION)
		delete_cmd_entry();
}

/*
 * The unset builtin command.  We unset the function before we unset the
 * variable to allow a function to be unset when there is a readonly variable
 * with the same name.
 */
static int
unsetcmd(int argc, char **argv)
{
	char **ap;
	int i;
	int flag = 0;
	int ret = 0;

	while ((i = nextopt("vf")) != '\0') {
		flag = i;
	}

	for (ap = argptr; *ap; ap++) {
		if (flag != 'f') {
			i = unsetvar(*ap);
			ret |= i;
			if (!(i & 2))
				continue;
		}
		if (flag != 'v')
			unsetfunc(*ap);
	}
	return ret & 1;
}


/*      setmode.c      */

#include <sys/times.h>

static const unsigned char timescmd_str[] = {
	' ',  offsetof(struct tms, tms_utime),
	'\n', offsetof(struct tms, tms_stime),
	' ',  offsetof(struct tms, tms_cutime),
	'\n', offsetof(struct tms, tms_cstime),
	0
};

static int
timescmd(int ac, char **av)
{
	long clk_tck, s, t;
	const unsigned char *p;
	struct tms buf;

	clk_tck = sysconf(_SC_CLK_TCK);
	times(&buf);

	p = timescmd_str;
	do {
		t = *(clock_t *)(((char *) &buf) + p[1]);
		s = t / clk_tck;
		out1fmt("%ldm%ld.%.3lds%c",
			s/60, s%60,
			((t - s * clk_tck) * 1000) / clk_tck,
			p[0]);
	} while (*(p += 2));

	return 0;
}

#if ENABLE_ASH_MATH_SUPPORT
static arith_t
dash_arith(const char *s)
{
	arith_t result;
	int errcode = 0;

	INT_OFF;
	result = arith(s, &errcode);
	if (errcode < 0) {
		if (errcode == -3)
			ash_msg_and_raise_error("exponent less than 0");
		if (errcode == -2)
			ash_msg_and_raise_error("divide by zero");
		if (errcode == -5)
			ash_msg_and_raise_error("expression recursion loop detected");
		raise_error_syntax(s);
	}
	INT_ON;

	return result;
}

/*
 *  The let builtin. partial stolen from GNU Bash, the Bourne Again SHell.
 *  Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc.
 *
 *  Copyright (C) 2003 Vladimir Oleynik <dzo@simtreas.ru>
 */
static int
letcmd(int argc, char **argv)
{
	char **ap;
	arith_t i = 0;

	ap = argv + 1;
	if (!*ap)
		ash_msg_and_raise_error("expression expected");
	for (ap = argv + 1; *ap; ap++) {
		i = dash_arith(*ap);
	}

	return !i;
}
#endif /* ASH_MATH_SUPPORT */


/* ============ miscbltin.c
 *
 * Miscellaneous builtins.
 */

#undef rflag

#if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 1
typedef enum __rlimit_resource rlim_t;
#endif

/*
 * The read builtin.  The -e option causes backslashes to escape the
 * following character.
 *
 * This uses unbuffered input, which may be avoidable in some cases.
 */
static int
readcmd(int argc, char **argv)
{
	char **ap;
	int backslash;
	char c;
	int rflag;
	char *prompt;
	const char *ifs;
	char *p;
	int startword;
	int status;
	int i;
#if ENABLE_ASH_READ_NCHARS
	int nch_flag = 0;
	int nchars = 0;
	int silent = 0;
	struct termios tty, old_tty;
#endif
#if ENABLE_ASH_READ_TIMEOUT
	fd_set set;
	struct timeval ts;

	ts.tv_sec = ts.tv_usec = 0;
#endif

	rflag = 0;
	prompt = NULL;
#if ENABLE_ASH_READ_NCHARS && ENABLE_ASH_READ_TIMEOUT
	while ((i = nextopt("p:rt:n:s")) != '\0')
#elif ENABLE_ASH_READ_NCHARS
	while ((i = nextopt("p:rn:s")) != '\0')
#elif ENABLE_ASH_READ_TIMEOUT
	while ((i = nextopt("p:rt:")) != '\0')
#else
	while ((i = nextopt("p:r")) != '\0')
#endif
	{
		switch (i) {
		case 'p':
			prompt = optionarg;
			break;
#if ENABLE_ASH_READ_NCHARS
		case 'n':
			nchars = strtol(optionarg, &p, 10);
			if (*p)
				ash_msg_and_raise_error("invalid count");
			nch_flag = (nchars > 0);
			break;
		case 's':
			silent = 1;
			break;
#endif
#if ENABLE_ASH_READ_TIMEOUT
		case 't':
			ts.tv_sec = strtol(optionarg, &p, 10);
			ts.tv_usec = 0;
			if (*p == '.') {
				char *p2;
				if (*++p) {
					int scale;
					ts.tv_usec = strtol(p, &p2, 10);
					if (*p2)
						ash_msg_and_raise_error("invalid timeout");
					scale = p2 - p;
					/* normalize to usec */
					if (scale > 6)
						ash_msg_and_raise_error("invalid timeout");
					while (scale++ < 6)
						ts.tv_usec *= 10;
				}
			} else if (*p) {
				ash_msg_and_raise_error("invalid timeout");
			}
			if ( ! ts.tv_sec && ! ts.tv_usec)
				ash_msg_and_raise_error("invalid timeout");
			break;
#endif
		case 'r':
			rflag = 1;
			break;
		default:
			break;
		}
	}
	if (prompt && isatty(0)) {
		out2str(prompt);
	}
	ap = argptr;
	if (*ap == NULL)
		ash_msg_and_raise_error("arg count");
	ifs = bltinlookup("IFS");
	if (ifs == NULL)
		ifs = defifs;
#if ENABLE_ASH_READ_NCHARS
	if (nch_flag || silent) {
		tcgetattr(0, &tty);
		old_tty = tty;
		if (nch_flag) {
			tty.c_lflag &= ~ICANON;
			tty.c_cc[VMIN] = nchars;
		}
		if (silent) {
			tty.c_lflag &= ~(ECHO|ECHOK|ECHONL);

		}
		tcsetattr(0, TCSANOW, &tty);
	}
#endif
#if ENABLE_ASH_READ_TIMEOUT
	if (ts.tv_sec || ts.tv_usec) {
		FD_ZERO (&set);
		FD_SET (0, &set);

		i = select(FD_SETSIZE, &set, NULL, NULL, &ts);
		if (!i) {
#if ENABLE_ASH_READ_NCHARS
			if (nch_flag)
				tcsetattr(0, TCSANOW, &old_tty);
#endif
			return 1;
		}
	}
#endif
	status = 0;
	startword = 1;
	backslash = 0;
	STARTSTACKSTR(p);
#if ENABLE_ASH_READ_NCHARS
	while (!nch_flag || nchars--)
#else
	for (;;)
#endif
	{
		if (read(0, &c, 1) != 1) {
			status = 1;
			break;
		}
		if (c == '\0')
			continue;
		if (backslash) {
			backslash = 0;
			if (c != '\n')
				goto put;
			continue;
		}
		if (!rflag && c == '\\') {
			backslash++;
			continue;
		}
		if (c == '\n')
			break;
		if (startword && *ifs == ' ' && strchr(ifs, c)) {
			continue;
		}
		startword = 0;
		if (ap[1] != NULL && strchr(ifs, c) != NULL) {
			STACKSTRNUL(p);
			setvar(*ap, stackblock(), 0);
			ap++;
			startword = 1;
			STARTSTACKSTR(p);
		} else {
 put:
			STPUTC(c, p);
		}
	}
#if ENABLE_ASH_READ_NCHARS
	if (nch_flag || silent)
		tcsetattr(0, TCSANOW, &old_tty);
#endif

	STACKSTRNUL(p);
	/* Remove trailing blanks */
	while ((char *)stackblock() <= --p && strchr(ifs, *p) != NULL)
		*p = '\0';
	setvar(*ap, stackblock(), 0);
	while (*++ap != NULL)
		setvar(*ap, nullstr, 0);
	return status;
}

static int
umaskcmd(int argc, char **argv)
{
	static const char permuser[3] = "ugo";
	static const char permmode[3] = "rwx";
	static const short int permmask[] = {
		S_IRUSR, S_IWUSR, S_IXUSR,
		S_IRGRP, S_IWGRP, S_IXGRP,
		S_IROTH, S_IWOTH, S_IXOTH
	};

	char *ap;
	mode_t mask;
	int i;
	int symbolic_mode = 0;

	while (nextopt("S") != '\0') {
		symbolic_mode = 1;
	}

	INT_OFF;
	mask = umask(0);
	umask(mask);
	INT_ON;

	ap = *argptr;
	if (ap == NULL) {
		if (symbolic_mode) {
			char buf[18];
			char *p = buf;

			for (i = 0; i < 3; i++) {
				int j;

				*p++ = permuser[i];
				*p++ = '=';
				for (j = 0; j < 3; j++) {
					if ((mask & permmask[3 * i + j]) == 0) {
						*p++ = permmode[j];
					}
				}
				*p++ = ',';
			}
			*--p = 0;
			puts(buf);
		} else {
			out1fmt("%.4o\n", mask);
		}
	} else {
		if (isdigit((unsigned char) *ap)) {
			mask = 0;
			do {
				if (*ap >= '8' || *ap < '0')
					ash_msg_and_raise_error(illnum, argv[1]);
				mask = (mask << 3) + (*ap - '0');
			} while (*++ap != '\0');
			umask(mask);
		} else {
			mask = ~mask & 0777;
			if (!bb_parse_mode(ap, &mask)) {
				ash_msg_and_raise_error("illegal mode: %s", ap);
			}
			umask(~mask & 0777);
		}
	}
	return 0;
}

/*
 * ulimit builtin
 *
 * This code, originally by Doug Gwyn, Doug Kingston, Eric Gisin, and
 * Michael Rendell was ripped from pdksh 5.0.8 and hacked for use with
 * ash by J.T. Conklin.
 *
 * Public domain.
 */

struct limits {
	const char *name;
	int     cmd;
	int     factor; /* multiply by to get rlim_{cur,max} values */
	char    option;
};

static const struct limits limits[] = {
#ifdef RLIMIT_CPU
	{ "time(seconds)",              RLIMIT_CPU,        1, 't' },
#endif
#ifdef RLIMIT_FSIZE
	{ "file(blocks)",               RLIMIT_FSIZE,    512, 'f' },
#endif
#ifdef RLIMIT_DATA
	{ "data(kbytes)",               RLIMIT_DATA,    1024, 'd' },
#endif
#ifdef RLIMIT_STACK
	{ "stack(kbytes)",              RLIMIT_STACK,   1024, 's' },
#endif
#ifdef  RLIMIT_CORE
	{ "coredump(blocks)",           RLIMIT_CORE,     512, 'c' },
#endif
#ifdef RLIMIT_RSS
	{ "memory(kbytes)",             RLIMIT_RSS,     1024, 'm' },
#endif
#ifdef RLIMIT_MEMLOCK
	{ "locked memory(kbytes)",      RLIMIT_MEMLOCK, 1024, 'l' },
#endif
#ifdef RLIMIT_NPROC
	{ "process",                    RLIMIT_NPROC,      1, 'p' },
#endif
#ifdef RLIMIT_NOFILE
	{ "nofiles",                    RLIMIT_NOFILE,     1, 'n' },
#endif
#ifdef RLIMIT_AS
	{ "vmemory(kbytes)",            RLIMIT_AS,      1024, 'v' },
#endif
#ifdef RLIMIT_LOCKS
	{ "locks",                      RLIMIT_LOCKS,      1, 'w' },
#endif
	{ NULL,                         0,                 0,  '\0' }
};

enum limtype { SOFT = 0x1, HARD = 0x2 };

static void
printlim(enum limtype how, const struct rlimit *limit,
			const struct limits *l)
{
	rlim_t val;

	val = limit->rlim_max;
	if (how & SOFT)
		val = limit->rlim_cur;

	if (val == RLIM_INFINITY)
		out1fmt("unlimited\n");
	else {
		val /= l->factor;
		out1fmt("%lld\n", (long long) val);
	}
}

static int
ulimitcmd(int argc, char **argv)
{
	int c;
	rlim_t val = 0;
	enum limtype how = SOFT | HARD;
	const struct limits *l;
	int set, all = 0;
	int optc, what;
	struct rlimit limit;

	what = 'f';
	while ((optc = nextopt("HSa"
#ifdef RLIMIT_CPU
				"t"
#endif
#ifdef RLIMIT_FSIZE
				"f"
#endif
#ifdef RLIMIT_DATA
				"d"
#endif
#ifdef RLIMIT_STACK
				"s"
#endif
#ifdef RLIMIT_CORE
				"c"
#endif
#ifdef RLIMIT_RSS
				"m"
#endif
#ifdef RLIMIT_MEMLOCK
				"l"
#endif
#ifdef RLIMIT_NPROC
				"p"
#endif
#ifdef RLIMIT_NOFILE
				"n"
#endif
#ifdef RLIMIT_AS
				"v"
#endif
#ifdef RLIMIT_LOCKS
				"w"
#endif
					)) != '\0')
		switch (optc) {
		case 'H':
			how = HARD;
			break;
		case 'S':
			how = SOFT;
			break;
		case 'a':
			all = 1;
			break;
		default:
			what = optc;
		}

	for (l = limits; l->option != what; l++)
		;

	set = *argptr ? 1 : 0;
	if (set) {
		char *p = *argptr;

		if (all || argptr[1])
			ash_msg_and_raise_error("too many arguments");
		if (strncmp(p, "unlimited\n", 9) == 0)
			val = RLIM_INFINITY;
		else {
			val = (rlim_t) 0;

			while ((c = *p++) >= '0' && c <= '9') {
				val = (val * 10) + (long)(c - '0');
				if (val < (rlim_t) 0)
					break;
			}
			if (c)
				ash_msg_and_raise_error("bad number");
			val *= l->factor;
		}
	}
	if (all) {
		for (l = limits; l->name; l++) {
			getrlimit(l->cmd, &limit);
			out1fmt("%-20s ", l->name);
			printlim(how, &limit, l);
		}
		return 0;
	}

	getrlimit(l->cmd, &limit);
	if (set) {
		if (how & HARD)
			limit.rlim_max = val;
		if (how & SOFT)
			limit.rlim_cur = val;
		if (setrlimit(l->cmd, &limit) < 0)
			ash_msg_and_raise_error("error setting limit (%m)");
	} else {
		printlim(how, &limit, l);
	}
	return 0;
}


/* ============ Math support */

#if ENABLE_ASH_MATH_SUPPORT

/* Copyright (c) 2001 Aaron Lehmann <aaronl@vitelus.com>

   Permission is hereby granted, free of charge, to any person obtaining
   a copy of this software and associated documentation files (the
   "Software"), to deal in the Software without restriction, including
   without limitation the rights to use, copy, modify, merge, publish,
   distribute, sublicense, and/or sell copies of the Software, and to
   permit persons to whom the Software is furnished to do so, subject to
   the following conditions:

   The above copyright notice and this permission notice shall be
   included in all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
   CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
   TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
   SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

/* This is my infix parser/evaluator. It is optimized for size, intended
 * as a replacement for yacc-based parsers. However, it may well be faster
 * than a comparable parser written in yacc. The supported operators are
 * listed in #defines below. Parens, order of operations, and error handling
 * are supported. This code is thread safe. The exact expression format should
 * be that which POSIX specifies for shells. */

/* The code uses a simple two-stack algorithm. See
 * http://www.onthenet.com.au/~grahamis/int2008/week02/lect02.html
 * for a detailed explanation of the infix-to-postfix algorithm on which
 * this is based (this code differs in that it applies operators immediately
 * to the stack instead of adding them to a queue to end up with an
 * expression). */

/* To use the routine, call it with an expression string and error return
 * pointer */

/*
 * Aug 24, 2001              Manuel Novoa III
 *
 * Reduced the generated code size by about 30% (i386) and fixed several bugs.
 *
 * 1) In arith_apply():
 *    a) Cached values of *numptr and &(numptr[-1]).
 *    b) Removed redundant test for zero denominator.
 *
 * 2) In arith():
 *    a) Eliminated redundant code for processing operator tokens by moving
 *       to a table-based implementation.  Also folded handling of parens
 *       into the table.
 *    b) Combined all 3 loops which called arith_apply to reduce generated
 *       code size at the cost of speed.
 *
 * 3) The following expressions were treated as valid by the original code:
 *       1()  ,    0!  ,    1 ( *3 )   .
 *    These bugs have been fixed by internally enclosing the expression in
 *    parens and then checking that all binary ops and right parens are
 *    preceded by a valid expression (NUM_TOKEN).
 *
 * Note: It may be desirable to replace Aaron's test for whitespace with
 * ctype's isspace() if it is used by another busybox applet or if additional
 * whitespace chars should be considered.  Look below the "#include"s for a
 * precompiler test.
 */

/*
 * Aug 26, 2001              Manuel Novoa III
 *
 * Return 0 for null expressions.  Pointed out by Vladimir Oleynik.
 *
 * Merge in Aaron's comments previously posted to the busybox list,
 * modified slightly to take account of my changes to the code.
 *
 */

/*
 *  (C) 2003 Vladimir Oleynik <dzo@simtreas.ru>
 *
 * - allow access to variable,
 *   used recursive find value indirection (c=2*2; a="c"; $((a+=2)) produce 6)
 * - realize assign syntax (VAR=expr, +=, *= etc)
 * - realize exponentiation (** operator)
 * - realize comma separated - expr, expr
 * - realise ++expr --expr expr++ expr--
 * - realise expr ? expr : expr (but, second expr calculate always)
 * - allow hexadecimal and octal numbers
 * - was restored loses XOR operator
 * - remove one goto label, added three ;-)
 * - protect $((num num)) as true zero expr (Manuel`s error)
 * - always use special isspace(), see comment from bash ;-)
 */

#define arith_isspace(arithval) \
	(arithval == ' ' || arithval == '\n' || arithval == '\t')

typedef unsigned char operator;

/* An operator's token id is a bit of a bitfield. The lower 5 bits are the
 * precedence, and 3 high bits are an ID unique across operators of that
 * precedence. The ID portion is so that multiple operators can have the
 * same precedence, ensuring that the leftmost one is evaluated first.
 * Consider * and /. */

#define tok_decl(prec,id) (((id)<<5)|(prec))
#define PREC(op) ((op) & 0x1F)

#define TOK_LPAREN tok_decl(0,0)

#define TOK_COMMA tok_decl(1,0)

#define TOK_ASSIGN tok_decl(2,0)
#define TOK_AND_ASSIGN tok_decl(2,1)
#define TOK_OR_ASSIGN tok_decl(2,2)
#define TOK_XOR_ASSIGN tok_decl(2,3)
#define TOK_PLUS_ASSIGN tok_decl(2,4)
#define TOK_MINUS_ASSIGN tok_decl(2,5)
#define TOK_LSHIFT_ASSIGN tok_decl(2,6)
#define TOK_RSHIFT_ASSIGN tok_decl(2,7)

#define TOK_MUL_ASSIGN tok_decl(3,0)
#define TOK_DIV_ASSIGN tok_decl(3,1)
#define TOK_REM_ASSIGN tok_decl(3,2)

/* all assign is right associativity and precedence eq, but (7+3)<<5 > 256 */
#define convert_prec_is_assing(prec) do { if (prec == 3) prec = 2; } while (0)

/* conditional is right associativity too */
#define TOK_CONDITIONAL tok_decl(4,0)
#define TOK_CONDITIONAL_SEP tok_decl(4,1)

#define TOK_OR tok_decl(5,0)

#define TOK_AND tok_decl(6,0)

#define TOK_BOR tok_decl(7,0)

#define TOK_BXOR tok_decl(8,0)

#define TOK_BAND tok_decl(9,0)

#define TOK_EQ tok_decl(10,0)
#define TOK_NE tok_decl(10,1)

#define TOK_LT tok_decl(11,0)
#define TOK_GT tok_decl(11,1)
#define TOK_GE tok_decl(11,2)
#define TOK_LE tok_decl(11,3)

#define TOK_LSHIFT tok_decl(12,0)
#define TOK_RSHIFT tok_decl(12,1)

#define TOK_ADD tok_decl(13,0)
#define TOK_SUB tok_decl(13,1)

#define TOK_MUL tok_decl(14,0)
#define TOK_DIV tok_decl(14,1)
#define TOK_REM tok_decl(14,2)

/* exponent is right associativity */
#define TOK_EXPONENT tok_decl(15,1)

/* For now unary operators. */
#define UNARYPREC 16
#define TOK_BNOT tok_decl(UNARYPREC,0)
#define TOK_NOT tok_decl(UNARYPREC,1)

#define TOK_UMINUS tok_decl(UNARYPREC+1,0)
#define TOK_UPLUS tok_decl(UNARYPREC+1,1)

#define PREC_PRE (UNARYPREC+2)

#define TOK_PRE_INC tok_decl(PREC_PRE, 0)
#define TOK_PRE_DEC tok_decl(PREC_PRE, 1)

#define PREC_POST (UNARYPREC+3)

#define TOK_POST_INC tok_decl(PREC_POST, 0)
#define TOK_POST_DEC tok_decl(PREC_POST, 1)

#define SPEC_PREC (UNARYPREC+4)

#define TOK_NUM tok_decl(SPEC_PREC, 0)
#define TOK_RPAREN tok_decl(SPEC_PREC, 1)

#define NUMPTR (*numstackptr)

static int
tok_have_assign(operator op)
{
	operator prec = PREC(op);

	convert_prec_is_assing(prec);
	return (prec == PREC(TOK_ASSIGN) ||
			prec == PREC_PRE || prec == PREC_POST);
}

static int
is_right_associativity(operator prec)
{
	return (prec == PREC(TOK_ASSIGN) || prec == PREC(TOK_EXPONENT)
	        || prec == PREC(TOK_CONDITIONAL));
}

typedef struct ARITCH_VAR_NUM {
	arith_t val;
	arith_t contidional_second_val;
	char contidional_second_val_initialized;
	char *var;      /* if NULL then is regular number,
			   else is variable name */
} v_n_t;

typedef struct CHK_VAR_RECURSIVE_LOOPED {
	const char *var;
	struct CHK_VAR_RECURSIVE_LOOPED *next;
} chk_var_recursive_looped_t;

static chk_var_recursive_looped_t *prev_chk_var_recursive;

static int
arith_lookup_val(v_n_t *t)
{
	if (t->var) {
		const char * p = lookupvar(t->var);

		if (p) {
			int errcode;

			/* recursive try as expression */
			chk_var_recursive_looped_t *cur;
			chk_var_recursive_looped_t cur_save;

			for (cur = prev_chk_var_recursive; cur; cur = cur->next) {
				if (strcmp(cur->var, t->var) == 0) {
					/* expression recursion loop detected */
					return -5;
				}
			}
			/* save current lookuped var name */
			cur = prev_chk_var_recursive;
			cur_save.var = t->var;
			cur_save.next = cur;
			prev_chk_var_recursive = &cur_save;

			t->val = arith (p, &errcode);
			/* restore previous ptr after recursiving */
			prev_chk_var_recursive = cur;
			return errcode;
		}
		/* allow undefined var as 0 */
		t->val = 0;
	}
	return 0;
}

/* "applying" a token means performing it on the top elements on the integer
 * stack. For a unary operator it will only change the top element, but a
 * binary operator will pop two arguments and push a result */
static int
arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr)
{
	v_n_t *numptr_m1;
	arith_t numptr_val, rez;
	int ret_arith_lookup_val;

	/* There is no operator that can work without arguments */
	if (NUMPTR == numstack) goto err;
	numptr_m1 = NUMPTR - 1;

	/* check operand is var with noninteger value */
	ret_arith_lookup_val = arith_lookup_val(numptr_m1);
	if (ret_arith_lookup_val)
		return ret_arith_lookup_val;

	rez = numptr_m1->val;
	if (op == TOK_UMINUS)
		rez *= -1;
	else if (op == TOK_NOT)
		rez = !rez;
	else if (op == TOK_BNOT)
		rez = ~rez;
	else if (op == TOK_POST_INC || op == TOK_PRE_INC)
		rez++;
	else if (op == TOK_POST_DEC || op == TOK_PRE_DEC)
		rez--;
	else if (op != TOK_UPLUS) {
		/* Binary operators */

		/* check and binary operators need two arguments */
		if (numptr_m1 == numstack) goto err;

		/* ... and they pop one */
		--NUMPTR;
		numptr_val = rez;
		if (op == TOK_CONDITIONAL) {
			if (! numptr_m1->contidional_second_val_initialized) {
				/* protect $((expr1 ? expr2)) without ": expr" */
				goto err;
			}
			rez = numptr_m1->contidional_second_val;
		} else if (numptr_m1->contidional_second_val_initialized) {
			/* protect $((expr1 : expr2)) without "expr ? " */
			goto err;
		}
		numptr_m1 = NUMPTR - 1;
		if (op != TOK_ASSIGN) {
			/* check operand is var with noninteger value for not '=' */
			ret_arith_lookup_val = arith_lookup_val(numptr_m1);
			if (ret_arith_lookup_val)
				return ret_arith_lookup_val;
		}
		if (op == TOK_CONDITIONAL) {
			numptr_m1->contidional_second_val = rez;
		}
		rez = numptr_m1->val;
		if (op == TOK_BOR || op == TOK_OR_ASSIGN)
			rez |= numptr_val;
		else if (op == TOK_OR)
			rez = numptr_val || rez;
		else if (op == TOK_BAND || op == TOK_AND_ASSIGN)
			rez &= numptr_val;
		else if (op == TOK_BXOR || op == TOK_XOR_ASSIGN)
			rez ^= numptr_val;
		else if (op == TOK_AND)
			rez = rez && numptr_val;
		else if (op == TOK_EQ)
			rez = (rez == numptr_val);
		else if (op == TOK_NE)
			rez = (rez != numptr_val);
		else if (op == TOK_GE)
			rez = (rez >= numptr_val);
		else if (op == TOK_RSHIFT || op == TOK_RSHIFT_ASSIGN)
			rez >>= numptr_val;
		else if (op == TOK_LSHIFT || op == TOK_LSHIFT_ASSIGN)
			rez <<= numptr_val;
		else if (op == TOK_GT)
			rez = (rez > numptr_val);
		else if (op == TOK_LT)
			rez = (rez < numptr_val);
		else if (op == TOK_LE)
			rez = (rez <= numptr_val);
		else if (op == TOK_MUL || op == TOK_MUL_ASSIGN)
			rez *= numptr_val;
		else if (op == TOK_ADD || op == TOK_PLUS_ASSIGN)
			rez += numptr_val;
		else if (op == TOK_SUB || op == TOK_MINUS_ASSIGN)
			rez -= numptr_val;
		else if (op == TOK_ASSIGN || op == TOK_COMMA)
			rez = numptr_val;
		else if (op == TOK_CONDITIONAL_SEP) {
			if (numptr_m1 == numstack) {
				/* protect $((expr : expr)) without "expr ? " */
				goto err;
			}
			numptr_m1->contidional_second_val_initialized = op;
			numptr_m1->contidional_second_val = numptr_val;
		} else if (op == TOK_CONDITIONAL) {
			rez = rez ?
				numptr_val : numptr_m1->contidional_second_val;
		} else if (op == TOK_EXPONENT) {
			if (numptr_val < 0)
				return -3;      /* exponent less than 0 */
			else {
				arith_t c = 1;

				if (numptr_val)
					while (numptr_val--)
						c *= rez;
				rez = c;
			}
		} else if (numptr_val==0)          /* zero divisor check */
			return -2;
		else if (op == TOK_DIV || op == TOK_DIV_ASSIGN)
			rez /= numptr_val;
		else if (op == TOK_REM || op == TOK_REM_ASSIGN)
			rez %= numptr_val;
	}
	if (tok_have_assign(op)) {
		char buf[sizeof(arith_t_type)*3 + 2];

		if (numptr_m1->var == NULL) {
			/* Hmm, 1=2 ? */
			goto err;
		}
		/* save to shell variable */
#if ENABLE_ASH_MATH_SUPPORT_64
		snprintf(buf, sizeof(buf), "%lld", (arith_t_type) rez);
#else
		snprintf(buf, sizeof(buf), "%ld", (arith_t_type) rez);
#endif
		setvar(numptr_m1->var, buf, 0);
		/* after saving, make previous value for v++ or v-- */
		if (op == TOK_POST_INC)
			rez--;
		else if (op == TOK_POST_DEC)
			rez++;
	}
	numptr_m1->val = rez;
	/* protect geting var value, is number now */
	numptr_m1->var = NULL;
	return 0;
 err:
	return -1;
}

/* longest must be first */
static const char op_tokens[] = {
	'<','<','=',0, TOK_LSHIFT_ASSIGN,
	'>','>','=',0, TOK_RSHIFT_ASSIGN,
	'<','<',    0, TOK_LSHIFT,
	'>','>',    0, TOK_RSHIFT,
	'|','|',    0, TOK_OR,
	'&','&',    0, TOK_AND,
	'!','=',    0, TOK_NE,
	'<','=',    0, TOK_LE,
	'>','=',    0, TOK_GE,
	'=','=',    0, TOK_EQ,
	'|','=',    0, TOK_OR_ASSIGN,
	'&','=',    0, TOK_AND_ASSIGN,
	'*','=',    0, TOK_MUL_ASSIGN,
	'/','=',    0, TOK_DIV_ASSIGN,
	'%','=',    0, TOK_REM_ASSIGN,
	'+','=',    0, TOK_PLUS_ASSIGN,
	'-','=',    0, TOK_MINUS_ASSIGN,
	'-','-',    0, TOK_POST_DEC,
	'^','=',    0, TOK_XOR_ASSIGN,
	'+','+',    0, TOK_POST_INC,
	'*','*',    0, TOK_EXPONENT,
	'!',        0, TOK_NOT,
	'<',        0, TOK_LT,
	'>',        0, TOK_GT,
	'=',        0, TOK_ASSIGN,
	'|',        0, TOK_BOR,
	'&',        0, TOK_BAND,
	'*',        0, TOK_MUL,
	'/',        0, TOK_DIV,
	'%',        0, TOK_REM,
	'+',        0, TOK_ADD,
	'-',        0, TOK_SUB,
	'^',        0, TOK_BXOR,
	/* uniq */
	'~',        0, TOK_BNOT,
	',',        0, TOK_COMMA,
	'?',        0, TOK_CONDITIONAL,
	':',        0, TOK_CONDITIONAL_SEP,
	')',        0, TOK_RPAREN,
	'(',        0, TOK_LPAREN,
	0
};
/* ptr to ")" */
#define endexpression &op_tokens[sizeof(op_tokens)-7]

static arith_t
arith(const char *expr, int *perrcode)
{
	char arithval; /* Current character under analysis */
	operator lasttok, op;
	operator prec;

	const char *p = endexpression;
	int errcode;

	size_t datasizes = strlen(expr) + 2;

	/* Stack of integers */
	/* The proof that there can be no more than strlen(startbuf)/2+1 integers
	 * in any given correct or incorrect expression is left as an exercise to
	 * the reader. */
	v_n_t *numstack = alloca(((datasizes)/2)*sizeof(v_n_t)),
				*numstackptr = numstack;
	/* Stack of operator tokens */
	operator *stack = alloca((datasizes) * sizeof(operator)),
				*stackptr = stack;

	*stackptr++ = lasttok = TOK_LPAREN;     /* start off with a left paren */
	*perrcode = errcode = 0;

	while (1) {
		arithval = *expr;
		if (arithval == 0) {
			if (p == endexpression) {
				/* Null expression. */
				return 0;
			}

			/* This is only reached after all tokens have been extracted from the
			 * input stream. If there are still tokens on the operator stack, they
			 * are to be applied in order. At the end, there should be a final
			 * result on the integer stack */

			if (expr != endexpression + 1) {
				/* If we haven't done so already, */
				/* append a closing right paren */
				expr = endexpression;
				/* and let the loop process it. */
				continue;
			}
			/* At this point, we're done with the expression. */
			if (numstackptr != numstack+1) {
				/* ... but if there isn't, it's bad */
 err:
				return (*perrcode = -1);
			}
			if (numstack->var) {
				/* expression is $((var)) only, lookup now */
				errcode = arith_lookup_val(numstack);
			}
 ret:
			*perrcode = errcode;
			return numstack->val;
		}

		/* Continue processing the expression. */
		if (arith_isspace(arithval)) {
			/* Skip whitespace */
			goto prologue;
		}
		p = endofname(expr);
		if (p != expr) {
			size_t var_name_size = (p-expr) + 1;  /* trailing zero */

			numstackptr->var = alloca(var_name_size);
			safe_strncpy(numstackptr->var, expr, var_name_size);
			expr = p;
 num:
			numstackptr->contidional_second_val_initialized = 0;
			numstackptr++;
			lasttok = TOK_NUM;
			continue;
		}
		if (isdigit(arithval)) {
			numstackptr->var = NULL;
#if ENABLE_ASH_MATH_SUPPORT_64
			numstackptr->val = strtoll(expr, (char **) &expr, 0);
#else
			numstackptr->val = strtol(expr, (char **) &expr, 0);
#endif
			goto num;
		}
		for (p = op_tokens; ; p++) {
			const char *o;

			if (*p == 0) {
				/* strange operator not found */
				goto err;
			}
			for (o = expr; *p && *o == *p; p++)
				o++;
			if (! *p) {
				/* found */
				expr = o - 1;
				break;
			}
			/* skip tail uncompared token */
			while (*p)
				p++;
			/* skip zero delim */
			p++;
		}
		op = p[1];

		/* post grammar: a++ reduce to num */
		if (lasttok == TOK_POST_INC || lasttok == TOK_POST_DEC)
			lasttok = TOK_NUM;

		/* Plus and minus are binary (not unary) _only_ if the last
		 * token was as number, or a right paren (which pretends to be
		 * a number, since it evaluates to one). Think about it.
		 * It makes sense. */
		if (lasttok != TOK_NUM) {
			switch (op) {
			case TOK_ADD:
				op = TOK_UPLUS;
				break;
			case TOK_SUB:
				op = TOK_UMINUS;
				break;
			case TOK_POST_INC:
				op = TOK_PRE_INC;
				break;
			case TOK_POST_DEC:
				op = TOK_PRE_DEC;
				break;
			}
		}
		/* We don't want a unary operator to cause recursive descent on the
		 * stack, because there can be many in a row and it could cause an
		 * operator to be evaluated before its argument is pushed onto the
		 * integer stack. */
		/* But for binary operators, "apply" everything on the operator
		 * stack until we find an operator with a lesser priority than the
		 * one we have just extracted. */
		/* Left paren is given the lowest priority so it will never be
		 * "applied" in this way.
		 * if associativity is right and priority eq, applied also skip
		 */
		prec = PREC(op);
		if ((prec > 0 && prec < UNARYPREC) || prec == SPEC_PREC) {
			/* not left paren or unary */
			if (lasttok != TOK_NUM) {
				/* binary op must be preceded by a num */
				goto err;
			}
			while (stackptr != stack) {
				if (op == TOK_RPAREN) {
					/* The algorithm employed here is simple: while we don't
					 * hit an open paren nor the bottom of the stack, pop
					 * tokens and apply them */
					if (stackptr[-1] == TOK_LPAREN) {
						--stackptr;
						/* Any operator directly after a */
						lasttok = TOK_NUM;
						/* close paren should consider itself binary */
						goto prologue;
					}
				} else {
					operator prev_prec = PREC(stackptr[-1]);

					convert_prec_is_assing(prec);
					convert_prec_is_assing(prev_prec);
					if (prev_prec < prec)
						break;
					/* check right assoc */
					if (prev_prec == prec && is_right_associativity(prec))
						break;
				}
				errcode = arith_apply(*--stackptr, numstack, &numstackptr);
				if (errcode) goto ret;
			}
			if (op == TOK_RPAREN) {
				goto err;
			}
		}

		/* Push this operator to the stack and remember it. */
		*stackptr++ = lasttok = op;
 prologue:
		++expr;
	} /* while */
}
#endif /* ASH_MATH_SUPPORT */


/* ============ main() and helpers */

/*
 * Called to exit the shell.
 */
static void exitshell(void) ATTRIBUTE_NORETURN;
static void
exitshell(void)
{
	struct jmploc loc;
	char *p;
	int status;

	status = exitstatus;
	TRACE(("pid %d, exitshell(%d)\n", getpid(), status));
	if (setjmp(loc.loc)) {
		if (exception == EXEXIT)
/* dash bug: it just does _exit(exitstatus) here
 * but we have to do setjobctl(0) first!
 * (bug is still not fixed in dash-0.5.3 - if you run dash
 * under Midnight Commander, on exit from dash MC is backgrounded) */
			status = exitstatus;
		goto out;
	}
	exception_handler = &loc;
	p = trap[0];
	if (p) {
		trap[0] = NULL;
		evalstring(p, 0);
	}
	flush_stdout_stderr();
 out:
	setjobctl(0);
	_exit(status);
	/* NOTREACHED */
}

static void
init(void)
{
	/* from input.c: */
	basepf.nextc = basepf.buf = basebuf;

	/* from trap.c: */
	signal(SIGCHLD, SIG_DFL);

	/* from var.c: */
	{
		char **envp;
		char ppid[sizeof(int)*3 + 1];
		const char *p;
		struct stat st1, st2;

		initvar();
		for (envp = environ; envp && *envp; envp++) {
			if (strchr(*envp, '=')) {
				setvareq(*envp, VEXPORT|VTEXTFIXED);
			}
		}

		snprintf(ppid, sizeof(ppid), "%u", (unsigned) getppid());
		setvar("PPID", ppid, 0);

		p = lookupvar("PWD");
		if (p)
			if (*p != '/' || stat(p, &st1) || stat(".", &st2)
			 || st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
				p = '\0';
		setpwd(p, 0);
	}
}

/*
 * Process the shell command line arguments.
 */
static void
procargs(int argc, char **argv)
{
	int i;
	const char *xminusc;
	char **xargv;

	xargv = argv;
	arg0 = xargv[0];
	if (argc > 0)
		xargv++;
	for (i = 0; i < NOPTS; i++)
		optlist[i] = 2;
	argptr = xargv;
	options(1);
	xargv = argptr;
	xminusc = minusc;
	if (*xargv == NULL) {
		if (xminusc)
			ash_msg_and_raise_error(bb_msg_requires_arg, "-c");
		sflag = 1;
	}
	if (iflag == 2 && sflag == 1 && isatty(0) && isatty(1))
		iflag = 1;
	if (mflag == 2)
		mflag = iflag;
	for (i = 0; i < NOPTS; i++)
		if (optlist[i] == 2)
			optlist[i] = 0;
#if DEBUG == 2
	debug = 1;
#endif
	/* POSIX 1003.2: first arg after -c cmd is $0, remainder $1... */
	if (xminusc) {
		minusc = *xargv++;
		if (*xargv)
			goto setarg0;
	} else if (!sflag) {
		setinputfile(*xargv, 0);
 setarg0:
		arg0 = *xargv++;
		commandname = arg0;
	}

	shellparam.p = xargv;
#if ENABLE_ASH_GETOPTS
	shellparam.optind = 1;
	shellparam.optoff = -1;
#endif
	/* assert(shellparam.malloc == 0 && shellparam.nparam == 0); */
	while (*xargv) {
		shellparam.nparam++;
		xargv++;
	}
	optschanged();
}

/*
 * Read /etc/profile or .profile.
 */
static void
read_profile(const char *name)
{
	int skip;

	if (setinputfile(name, INPUT_PUSH_FILE | INPUT_NOFILE_OK) < 0)
		return;
	skip = cmdloop(0);
	popfile();
	if (skip)
		exitshell();
}

/*
 * This routine is called when an error or an interrupt occurs in an
 * interactive shell and control is returned to the main command loop.
 */
static void
reset(void)
{
	/* from eval.c: */
	evalskip = 0;
	loopnest = 0;
	/* from input.c: */
	parselleft = parsenleft = 0;      /* clear input buffer */
	popallfiles();
	/* from parser.c: */
	tokpushback = 0;
	checkkwd = 0;
	/* from redir.c: */
	clearredir(0);
}

#if PROFILE
static short profile_buf[16384];
extern int etext();
#endif

/*
 * Main routine.  We initialize things, parse the arguments, execute
 * profiles if we're a login shell, and then call cmdloop to execute
 * commands.  The setjmp call sets up the location to jump to when an
 * exception occurs.  When an exception occurs the variable "state"
 * is used to figure out how far we had gotten.
 */
int ash_main(int argc, char **argv);
int ash_main(int argc, char **argv)
{
	char *shinit;
	volatile int state;
	struct jmploc jmploc;
	struct stackmark smark;

#ifdef __GLIBC__
	dash_errno = __errno_location();
#endif

#if PROFILE
	monitor(4, etext, profile_buf, sizeof(profile_buf), 50);
#endif

#if ENABLE_FEATURE_EDITING
	line_input_state = new_line_input_t(FOR_SHELL | WITH_PATH_LOOKUP);
#endif
	state = 0;
	if (setjmp(jmploc.loc)) {
		int e;
		int s;

		reset();

		e = exception;
		if (e == EXERROR)
			exitstatus = 2;
		s = state;
		if (e == EXEXIT || s == 0 || iflag == 0 || shlvl)
			exitshell();

		if (e == EXINT) {
			outcslow('\n', stderr);
		}
		popstackmark(&smark);
		FORCE_INT_ON; /* enable interrupts */
		if (s == 1)
			goto state1;
		if (s == 2)
			goto state2;
		if (s == 3)
			goto state3;
		goto state4;
	}
	exception_handler = &jmploc;
#if DEBUG
	opentrace();
	trace_puts("Shell args: ");
	trace_puts_args(argv);
#endif
	rootpid = getpid();

#if ENABLE_ASH_RANDOM_SUPPORT
	rseed = rootpid + time(NULL);
#endif
	init();
	setstackmark(&smark);
	procargs(argc, argv);
#if ENABLE_FEATURE_EDITING_SAVEHISTORY
	if (iflag) {
		const char *hp = lookupvar("HISTFILE");

		if (hp == NULL) {
			hp = lookupvar("HOME");
			if (hp != NULL) {
				char *defhp = concat_path_file(hp, ".ash_history");
				setvar("HISTFILE", defhp, 0);
				free(defhp);
			}
		}
	}
#endif
	if (argv[0] && argv[0][0] == '-')
		isloginsh = 1;
	if (isloginsh) {
		state = 1;
		read_profile("/etc/profile");
 state1:
		state = 2;
		read_profile(".profile");
	}
 state2:
	state = 3;
	if (
#ifndef linux
	 getuid() == geteuid() && getgid() == getegid() &&
#endif
	 iflag
	) {
		shinit = lookupvar("ENV");
		if (shinit != NULL && *shinit != '\0') {
			read_profile(shinit);
		}
	}
 state3:
	state = 4;
	if (minusc)
		evalstring(minusc, 0);

	if (sflag || minusc == NULL) {
#if ENABLE_FEATURE_EDITING_SAVEHISTORY
		if ( iflag ) {
			const char *hp = lookupvar("HISTFILE");

			if (hp != NULL)
				line_input_state->hist_file = hp;
		}
#endif
 state4: /* XXX ??? - why isn't this before the "if" statement */
		cmdloop(1);
	}
#if PROFILE
	monitor(0);
#endif
#ifdef GPROF
	{
		extern void _mcleanup(void);
		_mcleanup();
	}
#endif
	exitshell();
	/* NOTREACHED */
}

#if DEBUG
const char *applet_name = "debug stuff usage";
int main(int argc, char **argv)
{
	return ash_main(argc, argv);
}
#endif


/*-
 * Copyright (c) 1989, 1991, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */