aboutsummaryrefslogtreecommitdiff
path: root/shell/hush.c
blob: 831443e2e2b88b6e37fd4f5cefbb9a28552147c7 (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
/* vi: set sw=4 ts=4: */
/*
 * A prototype Bourne shell grammar parser.
 * Intended to follow the original Thompson and Ritchie
 * "small and simple is beautiful" philosophy, which
 * incidentally is a good match to today's BusyBox.
 *
 * Copyright (C) 2000,2001  Larry Doolittle <larry@doolittle.boa.org>
 * Copyright (C) 2008,2009  Denys Vlasenko <vda.linux@googlemail.com>
 *
 * Credits:
 *      The parser routines proper are all original material, first
 *      written Dec 2000 and Jan 2001 by Larry Doolittle.  The
 *      execution engine, the builtins, and much of the underlying
 *      support has been adapted from busybox-0.49pre's lash, which is
 *      Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *      written by Erik Andersen <andersen@codepoet.org>.  That, in turn,
 *      is based in part on ladsh.c, by Michael K. Johnson and Erik W.
 *      Troan, which they placed in the public domain.  I don't know
 *      how much of the Johnson/Troan code has survived the repeated
 *      rewrites.
 *
 * Other credits:
 *      o_addchr derived from similar w_addchar function in glibc-2.2.
 *      parse_redirect, redirect_opt_num, and big chunks of main
 *      and many builtins derived from contributions by Erik Andersen.
 *      Miscellaneous bugfixes from Matt Kraai.
 *
 * There are two big (and related) architecture differences between
 * this parser and the lash parser.  One is that this version is
 * actually designed from the ground up to understand nearly all
 * of the Bourne grammar.  The second, consequential change is that
 * the parser and input reader have been turned inside out.  Now,
 * the parser is in control, and asks for input as needed.  The old
 * way had the input reader in control, and it asked for parsing to
 * take place as needed.  The new way makes it much easier to properly
 * handle the recursion implicit in the various substitutions, especially
 * across continuation lines.
 *
 * TODOs:
 *      grep for "TODO" and fix (some of them are easy)
 *      special variables (done: PWD, PPID, RANDOM)
 *      tilde expansion
 *      aliases
 *      follow IFS rules more precisely, including update semantics
 *      builtins mandated by standards we don't support:
 *          [un]alias, command, fc, getopts, newgrp, readonly, times
 *      make complex ${var%...} constructs support optional
 *      make here documents optional
 *
 * Bash compat TODO:
 *      redirection of stdout+stderr: &> and >&
 *      subst operator: ${var/[/]expr/expr}
 *      brace expansion: one/{two,three,four}
 *      reserved words: function select
 *      advanced test: [[ ]]
 *      process substitution: <(list) and >(list)
 *      =~: regex operator
 *      let EXPR [EXPR...]
 *          Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
 *          If the last arg evaluates to 0, let returns 1; 0 otherwise.
 *          NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
 *      ((EXPR))
 *          The EXPR is evaluated according to ARITHMETIC EVALUATION.
 *          This is exactly equivalent to let "EXPR".
 *      $[EXPR]: synonym for $((EXPR))
 *      export builtin should be special, its arguments are assignments
 *          and therefore expansion of them should be "one-word" expansion:
 *              $ export i=`echo 'a  b'` # export has one arg: "i=a  b"
 *          compare with:
 *              $ ls i=`echo 'a  b'`     # ls has two args: "i=a" and "b"
 *              ls: cannot access i=a: No such file or directory
 *              ls: cannot access b: No such file or directory
 *          Note1: same applies to local builtin.
 *          Note2: bash 3.2.33(1) does this only if export word itself
 *          is not quoted:
 *              $ export i=`echo 'aaa  bbb'`; echo "$i"
 *              aaa  bbb
 *              $ "export" i=`echo 'aaa  bbb'`; echo "$i"
 *              aaa
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */
#include "busybox.h"  /* for APPLET_IS_NOFORK/NOEXEC */
#include <malloc.h>   /* for malloc_trim */
#include <glob.h>
/* #include <dmalloc.h> */
#if ENABLE_HUSH_CASE
# include <fnmatch.h>
#endif

#include "shell_common.h"
#include "math.h"
#include "match.h"
#if ENABLE_HUSH_RANDOM_SUPPORT
# include "random.h"
#else
# define CLEAR_RANDOM_T(rnd) ((void)0)
#endif
#ifndef PIPE_BUF
# define PIPE_BUF 4096  /* amount of buffering in a pipe */
#endif


/* Build knobs */
#define LEAK_HUNTING 0
#define BUILD_AS_NOMMU 0
/* Enable/disable sanity checks. Ok to enable in production,
 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
 * Keeping 1 for now even in released versions.
 */
#define HUSH_DEBUG 1
/* Slightly bigger (+200 bytes), but faster hush.
 * So far it only enables a trick with counting SIGCHLDs and forks,
 * which allows us to do fewer waitpid's.
 * (we can detect a case where neither forks were done nor SIGCHLDs happened
 * and therefore waitpid will return the same result as last time)
 */
#define ENABLE_HUSH_FAST 0


#if BUILD_AS_NOMMU
# undef BB_MMU
# undef USE_FOR_NOMMU
# undef USE_FOR_MMU
# define BB_MMU 0
# define USE_FOR_NOMMU(...) __VA_ARGS__
# define USE_FOR_MMU(...)
#endif

#include "NUM_APPLETS.h"
#if NUM_APPLETS == 1
/* STANDALONE does not make sense, and won't compile */
# undef CONFIG_FEATURE_SH_STANDALONE
# undef ENABLE_FEATURE_SH_STANDALONE
# undef IF_FEATURE_SH_STANDALONE
# undef IF_NOT_FEATURE_SH_STANDALONE
# define ENABLE_FEATURE_SH_STANDALONE 0
# define IF_FEATURE_SH_STANDALONE(...)
# define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
#endif

#if !ENABLE_HUSH_INTERACTIVE
# undef ENABLE_FEATURE_EDITING
# define ENABLE_FEATURE_EDITING 0
# undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
# define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
#endif

/* Do we support ANY keywords? */
#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
# define HAS_KEYWORDS 1
# define IF_HAS_KEYWORDS(...) __VA_ARGS__
# define IF_HAS_NO_KEYWORDS(...)
#else
# define HAS_KEYWORDS 0
# define IF_HAS_KEYWORDS(...)
# define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
#endif

/* If you comment out one of these below, it will be #defined later
 * to perform debug printfs to stderr: */
#define debug_printf(...)        do {} while (0)
/* Finer-grained debug switches */
#define debug_printf_parse(...)  do {} while (0)
#define debug_print_tree(a, b)   do {} while (0)
#define debug_printf_exec(...)   do {} while (0)
#define debug_printf_env(...)    do {} while (0)
#define debug_printf_jobs(...)   do {} while (0)
#define debug_printf_expand(...) do {} while (0)
#define debug_printf_varexp(...) do {} while (0)
#define debug_printf_glob(...)   do {} while (0)
#define debug_printf_list(...)   do {} while (0)
#define debug_printf_subst(...)  do {} while (0)
#define debug_printf_clean(...)  do {} while (0)

#define ERR_PTR ((void*)(long)1)

#define JOB_STATUS_FORMAT    "[%d] %-22s %.40s\n"

#define _SPECIAL_VARS_STR     "_*@$!?#"
#define SPECIAL_VARS_STR     ("_*@$!?#" + 1)
#define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)

#define SPECIAL_VAR_SYMBOL   3

struct variable;

static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;

/* This supports saving pointers malloced in vfork child,
 * to be freed in the parent.
 */
#if !BB_MMU
typedef struct nommu_save_t {
	char **new_env;
	struct variable *old_vars;
	char **argv;
	char **argv_from_re_execing;
} nommu_save_t;
#endif

typedef enum reserved_style {
	RES_NONE  = 0,
#if ENABLE_HUSH_IF
	RES_IF    ,
	RES_THEN  ,
	RES_ELIF  ,
	RES_ELSE  ,
	RES_FI    ,
#endif
#if ENABLE_HUSH_LOOPS
	RES_FOR   ,
	RES_WHILE ,
	RES_UNTIL ,
	RES_DO    ,
	RES_DONE  ,
#endif
#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
	RES_IN    ,
#endif
#if ENABLE_HUSH_CASE
	RES_CASE  ,
	/* three pseudo-keywords support contrived "case" syntax: */
	RES_CASE_IN,   /* "case ... IN", turns into RES_MATCH when IN is observed */
	RES_MATCH ,    /* "word)" */
	RES_CASE_BODY, /* "this command is inside CASE" */
	RES_ESAC  ,
#endif
	RES_XXXX  ,
	RES_SNTX
} reserved_style;

typedef struct o_string {
	char *data;
	int length; /* position where data is appended */
	int maxlen;
	/* Protect newly added chars against globbing
	 * (by prepending \ to *, ?, [, \) */
	smallint o_escape;
	smallint o_glob;
	/* At least some part of the string was inside '' or "",
	 * possibly empty one: word"", wo''rd etc. */
	smallint o_quoted;
	smallint has_empty_slot;
	smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
} o_string;
enum {
	MAYBE_ASSIGNMENT = 0,
	DEFINITELY_ASSIGNMENT = 1,
	NOT_ASSIGNMENT = 2,
	WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
};
/* Used for initialization: o_string foo = NULL_O_STRING; */
#define NULL_O_STRING { NULL }

/* I can almost use ordinary FILE*.  Is open_memstream() universally
 * available?  Where is it documented? */
typedef struct in_str {
	const char *p;
	/* eof_flag=1: last char in ->p is really an EOF */
	char eof_flag; /* meaningless if ->p == NULL */
	char peek_buf[2];
#if ENABLE_HUSH_INTERACTIVE
	smallint promptme;
	smallint promptmode; /* 0: PS1, 1: PS2 */
#endif
	FILE *file;
	int (*get) (struct in_str *) FAST_FUNC;
	int (*peek) (struct in_str *) FAST_FUNC;
} in_str;
#define i_getch(input) ((input)->get(input))
#define i_peek(input) ((input)->peek(input))

/* The descrip member of this structure is only used to make
 * debugging output pretty */
static const struct {
	int mode;
	signed char default_fd;
	char descrip[3];
} redir_table[] = {
	{ O_RDONLY,                  0, "<"  },
	{ O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
	{ O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
	{ O_CREAT|O_RDWR,            1, "<>" },
	{ O_RDONLY,                  0, "<<" },
/* Should not be needed. Bogus default_fd helps in debugging */
/*	{ O_RDONLY,                 77, "<<" }, */
};

struct redir_struct {
	struct redir_struct *next;
	char *rd_filename;          /* filename */
	int rd_fd;                  /* fd to redirect */
	/* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
	int rd_dup;
	smallint rd_type;           /* (enum redir_type) */
	/* note: for heredocs, rd_filename contains heredoc delimiter,
	 * and subsequently heredoc itself; and rd_dup is a bitmask:
	 * bit 0: do we need to trim leading tabs?
	 * bit 1: is heredoc quoted (<<'delim' syntax) ?
	 */
};
typedef enum redir_type {
	REDIRECT_INPUT     = 0,
	REDIRECT_OVERWRITE = 1,
	REDIRECT_APPEND    = 2,
	REDIRECT_IO        = 3,
	REDIRECT_HEREDOC   = 4,
	REDIRECT_HEREDOC2  = 5, /* REDIRECT_HEREDOC after heredoc is loaded */

	REDIRFD_CLOSE      = -3,
	REDIRFD_SYNTAX_ERR = -2,
	REDIRFD_TO_FILE    = -1,
	/* otherwise, rd_fd is redirected to rd_dup */

	HEREDOC_SKIPTABS = 1,
	HEREDOC_QUOTED   = 2,
} redir_type;


struct command {
	pid_t pid;                  /* 0 if exited */
	int assignment_cnt;         /* how many argv[i] are assignments? */
	smallint is_stopped;        /* is the command currently running? */
	smallint cmd_type;          /* CMD_xxx */
#define CMD_NORMAL   0
#define CMD_SUBSHELL 1

/* used for "[[ EXPR ]]" */
#if ENABLE_HUSH_BASH_COMPAT
# define CMD_SINGLEWORD_NOGLOB 2
#endif

/* used for "export noglob=* glob* a=`echo a b`" */
//#define CMD_SINGLEWORD_NOGLOB_COND 3
// It is hard to implement correctly, it adds significant amounts of tricky code,
// and all this is only useful for really obscure export statements
// almost nobody would use anyway. #ifdef CMD_SINGLEWORD_NOGLOB_COND
// guards the code which implements it, but I have doubts it works
// in all cases (especially with mixed globbed/non-globbed arguments)

#if ENABLE_HUSH_FUNCTIONS
# define CMD_FUNCDEF 3
#endif

	/* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
	struct pipe *group;
#if !BB_MMU
	char *group_as_string;
#endif
#if ENABLE_HUSH_FUNCTIONS
	struct function *child_func;
/* This field is used to prevent a bug here:
 * while...do f1() {a;}; f1; f1() {b;}; f1; done
 * When we execute "f1() {a;}" cmd, we create new function and clear
 * cmd->group, cmd->group_as_string, cmd->argv[0].
 * When we execute "f1() {b;}", we notice that f1 exists,
 * and that its "parent cmd" struct is still "alive",
 * we put those fields back into cmd->xxx
 * (struct function has ->parent_cmd ptr to facilitate that).
 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
 * Without this trick, loop would execute a;b;b;b;...
 * instead of correct sequence a;b;a;b;...
 * When command is freed, it severs the link
 * (sets ->child_func->parent_cmd to NULL).
 */
#endif
	char **argv;                /* command name and arguments */
/* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
 * and on execution these are substituted with their values.
 * Substitution can make _several_ words out of one argv[n]!
 * Example: argv[0]=='.^C*^C.' here: echo .$*.
 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
 */
	struct redir_struct *redirects; /* I/O redirections */
};
/* Is there anything in this command at all? */
#define IS_NULL_CMD(cmd) \
	(!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)


struct pipe {
	struct pipe *next;
	int num_cmds;               /* total number of commands in pipe */
	int alive_cmds;             /* number of commands running (not exited) */
	int stopped_cmds;           /* number of commands alive, but stopped */
#if ENABLE_HUSH_JOB
	int jobid;                  /* job number */
	pid_t pgrp;                 /* process group ID for the job */
	char *cmdtext;              /* name of job */
#endif
	struct command *cmds;       /* array of commands in pipe */
	smallint followup;          /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
	IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
	IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
};
typedef enum pipe_style {
	PIPE_SEQ = 1,
	PIPE_AND = 2,
	PIPE_OR  = 3,
	PIPE_BG  = 4,
} pipe_style;
/* Is there anything in this pipe at all? */
#define IS_NULL_PIPE(pi) \
	((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))

/* This holds pointers to the various results of parsing */
struct parse_context {
	/* linked list of pipes */
	struct pipe *list_head;
	/* last pipe (being constructed right now) */
	struct pipe *pipe;
	/* last command in pipe (being constructed right now) */
	struct command *command;
	/* last redirect in command->redirects list */
	struct redir_struct *pending_redirect;
#if !BB_MMU
	o_string as_string;
#endif
#if HAS_KEYWORDS
	smallint ctx_res_w;
	smallint ctx_inverted; /* "! cmd | cmd" */
#if ENABLE_HUSH_CASE
	smallint ctx_dsemicolon; /* ";;" seen */
#endif
	/* bitmask of FLAG_xxx, for figuring out valid reserved words */
	int old_flag;
	/* group we are enclosed in:
	 * example: "if pipe1; pipe2; then pipe3; fi"
	 * when we see "if" or "then", we malloc and copy current context,
	 * and make ->stack point to it. then we parse pipeN.
	 * when closing "then" / fi" / whatever is found,
	 * we move list_head into ->stack->command->group,
	 * copy ->stack into current context, and delete ->stack.
	 * (parsing of { list } and ( list ) doesn't use this method)
	 */
	struct parse_context *stack;
#endif
};

/* On program start, environ points to initial environment.
 * putenv adds new pointers into it, unsetenv removes them.
 * Neither of these (de)allocates the strings.
 * setenv allocates new strings in malloc space and does putenv,
 * and thus setenv is unusable (leaky) for shell's purposes */
#define setenv(...) setenv_is_leaky_dont_use()
struct variable {
	struct variable *next;
	char *varstr;        /* points to "name=" portion */
#if ENABLE_HUSH_LOCAL
	unsigned func_nest_level;
#endif
	int max_len;         /* if > 0, name is part of initial env; else name is malloced */
	smallint flg_export; /* putenv should be done on this var */
	smallint flg_read_only;
};

enum {
	BC_BREAK = 1,
	BC_CONTINUE = 2,
};

#if ENABLE_HUSH_FUNCTIONS
struct function {
	struct function *next;
	char *name;
	struct command *parent_cmd;
	struct pipe *body;
# if !BB_MMU
	char *body_as_string;
# endif
};
#endif


/* "Globals" within this file */
/* Sorted roughly by size (smaller offsets == smaller code) */
struct globals {
	/* interactive_fd != 0 means we are an interactive shell.
	 * If we are, then saved_tty_pgrp can also be != 0, meaning
	 * that controlling tty is available. With saved_tty_pgrp == 0,
	 * job control still works, but terminal signals
	 * (^C, ^Z, ^Y, ^\) won't work at all, and background
	 * process groups can only be created with "cmd &".
	 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
	 * to give tty to the foreground process group,
	 * and will take it back when the group is stopped (^Z)
	 * or killed (^C).
	 */
#if ENABLE_HUSH_INTERACTIVE
	/* 'interactive_fd' is a fd# open to ctty, if we have one
	 * _AND_ if we decided to act interactively */
	int interactive_fd;
	const char *PS1;
	const char *PS2;
# define G_interactive_fd (G.interactive_fd)
#else
# define G_interactive_fd 0
#endif
#if ENABLE_FEATURE_EDITING
	line_input_t *line_input_state;
#endif
	pid_t root_pid;
	pid_t root_ppid;
	pid_t last_bg_pid;
#if ENABLE_HUSH_RANDOM_SUPPORT
	random_t random_gen;
#endif
#if ENABLE_HUSH_JOB
	int run_list_level;
	int last_jobid;
	pid_t saved_tty_pgrp;
	struct pipe *job_list;
# define G_saved_tty_pgrp (G.saved_tty_pgrp)
#else
# define G_saved_tty_pgrp 0
#endif
	smallint flag_SIGINT;
#if ENABLE_HUSH_LOOPS
	smallint flag_break_continue;
#endif
#if ENABLE_HUSH_FUNCTIONS
	/* 0: outside of a function (or sourced file)
	 * -1: inside of a function, ok to use return builtin
	 * 1: return is invoked, skip all till end of func
	 */
	smallint flag_return_in_progress;
#endif
	smallint fake_mode;
	smallint exiting; /* used to prevent EXIT trap recursion */
	/* These four support $?, $#, and $1 */
	smalluint last_exitcode;
	/* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
	smalluint global_args_malloced;
	smalluint inherited_set_is_saved;
	/* how many non-NULL argv's we have. NB: $# + 1 */
	int global_argc;
	char **global_argv;
#if !BB_MMU
	char *argv0_for_re_execing;
#endif
#if ENABLE_HUSH_LOOPS
	unsigned depth_break_continue;
	unsigned depth_of_loop;
#endif
	const char *ifs;
	const char *cwd;
	struct variable *top_var; /* = &G.shell_ver (set in main()) */
	struct variable shell_ver;
#if ENABLE_HUSH_FUNCTIONS
	struct function *top_func;
# if ENABLE_HUSH_LOCAL
	struct variable **shadowed_vars_pp;
	unsigned func_nest_level;
# endif
#endif
	/* Signal and trap handling */
#if ENABLE_HUSH_FAST
	unsigned count_SIGCHLD;
	unsigned handled_SIGCHLD;
	smallint we_have_children;
#endif
	/* which signals have non-DFL handler (even with no traps set)? */
	unsigned non_DFL_mask;
	char **traps; /* char *traps[NSIG] */
	sigset_t blocked_set;
	sigset_t inherited_set;
#if HUSH_DEBUG
	unsigned long memleak_value;
	int debug_indent;
#endif
	char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
};
#define G (*ptr_to_globals)
/* Not #defining name to G.name - this quickly gets unwieldy
 * (too many defines). Also, I actually prefer to see when a variable
 * is global, thus "G." prefix is a useful hint */
#define INIT_G() do { \
	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
} while (0)


/* Function prototypes for builtins */
static int builtin_cd(char **argv) FAST_FUNC;
static int builtin_echo(char **argv) FAST_FUNC;
static int builtin_eval(char **argv) FAST_FUNC;
static int builtin_exec(char **argv) FAST_FUNC;
static int builtin_exit(char **argv) FAST_FUNC;
static int builtin_export(char **argv) FAST_FUNC;
#if ENABLE_HUSH_JOB
static int builtin_fg_bg(char **argv) FAST_FUNC;
static int builtin_jobs(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_HELP
static int builtin_help(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_LOCAL
static int builtin_local(char **argv) FAST_FUNC;
#endif
#if HUSH_DEBUG
static int builtin_memleak(char **argv) FAST_FUNC;
#endif
#if ENABLE_PRINTF
static int builtin_printf(char **argv) FAST_FUNC;
#endif
static int builtin_pwd(char **argv) FAST_FUNC;
static int builtin_read(char **argv) FAST_FUNC;
static int builtin_set(char **argv) FAST_FUNC;
static int builtin_shift(char **argv) FAST_FUNC;
static int builtin_source(char **argv) FAST_FUNC;
static int builtin_test(char **argv) FAST_FUNC;
static int builtin_trap(char **argv) FAST_FUNC;
static int builtin_type(char **argv) FAST_FUNC;
static int builtin_true(char **argv) FAST_FUNC;
static int builtin_umask(char **argv) FAST_FUNC;
static int builtin_unset(char **argv) FAST_FUNC;
static int builtin_wait(char **argv) FAST_FUNC;
#if ENABLE_HUSH_LOOPS
static int builtin_break(char **argv) FAST_FUNC;
static int builtin_continue(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_FUNCTIONS
static int builtin_return(char **argv) FAST_FUNC;
#endif

/* Table of built-in functions.  They can be forked or not, depending on
 * context: within pipes, they fork.  As simple commands, they do not.
 * When used in non-forking context, they can change global variables
 * in the parent shell process.  If forked, of course they cannot.
 * For example, 'unset foo | whatever' will parse and run, but foo will
 * still be set at the end. */
struct built_in_command {
	const char *b_cmd;
	int (*b_function)(char **argv) FAST_FUNC;
#if ENABLE_HUSH_HELP
	const char *b_descr;
# define BLTIN(cmd, func, help) { cmd, func, help }
#else
# define BLTIN(cmd, func, help) { cmd, func }
#endif
};

static const struct built_in_command bltins1[] = {
	BLTIN("."        , builtin_source  , "Run commands in a file"),
	BLTIN(":"        , builtin_true    , NULL),
#if ENABLE_HUSH_JOB
	BLTIN("bg"       , builtin_fg_bg   , "Resume a job in the background"),
#endif
#if ENABLE_HUSH_LOOPS
	BLTIN("break"    , builtin_break   , "Exit from a loop"),
#endif
	BLTIN("cd"       , builtin_cd      , "Change directory"),
#if ENABLE_HUSH_LOOPS
	BLTIN("continue" , builtin_continue, "Start new loop iteration"),
#endif
	BLTIN("eval"     , builtin_eval    , "Construct and run shell command"),
	BLTIN("exec"     , builtin_exec    , "Execute command, don't return to shell"),
	BLTIN("exit"     , builtin_exit    , "Exit"),
	BLTIN("export"   , builtin_export  , "Set environment variables"),
#if ENABLE_HUSH_JOB
	BLTIN("fg"       , builtin_fg_bg   , "Bring job into the foreground"),
#endif
#if ENABLE_HUSH_HELP
	BLTIN("help"     , builtin_help    , NULL),
#endif
#if ENABLE_HUSH_JOB
	BLTIN("jobs"     , builtin_jobs    , "List jobs"),
#endif
#if ENABLE_HUSH_LOCAL
	BLTIN("local"    , builtin_local   , "Set local variables"),
#endif
#if HUSH_DEBUG
	BLTIN("memleak"  , builtin_memleak , NULL),
#endif
	BLTIN("read"     , builtin_read    , "Input into variable"),
#if ENABLE_HUSH_FUNCTIONS
	BLTIN("return"   , builtin_return  , "Return from a function"),
#endif
	BLTIN("set"      , builtin_set     , "Set/unset positional parameters"),
	BLTIN("shift"    , builtin_shift   , "Shift positional parameters"),
#if ENABLE_HUSH_BASH_COMPAT
	BLTIN("source"   , builtin_source  , "Run commands in a file"),
#endif
	BLTIN("trap"     , builtin_trap    , "Trap signals"),
	BLTIN("type"     , builtin_type    , "Show command type"),
	BLTIN("ulimit"   , shell_builtin_ulimit  , "Control resource limits"),
	BLTIN("umask"    , builtin_umask   , "Set file creation mask"),
	BLTIN("unset"    , builtin_unset   , "Unset variables"),
	BLTIN("wait"     , builtin_wait    , "Wait for process"),
};
/* For now, echo and test are unconditionally enabled.
 * Maybe make it configurable? */
static const struct built_in_command bltins2[] = {
	BLTIN("["        , builtin_test    , NULL),
	BLTIN("echo"     , builtin_echo    , NULL),
#if ENABLE_PRINTF
	BLTIN("printf"   , builtin_printf  , NULL),
#endif
	BLTIN("pwd"      , builtin_pwd     , NULL),
	BLTIN("test"     , builtin_test    , NULL),
};


/* Debug printouts.
 */
#if HUSH_DEBUG
/* prevent disasters with G.debug_indent < 0 */
# define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
# define debug_enter() (G.debug_indent++)
# define debug_leave() (G.debug_indent--)
#else
# define indent()      ((void)0)
# define debug_enter() ((void)0)
# define debug_leave() ((void)0)
#endif

#ifndef debug_printf
# define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
#endif

#ifndef debug_printf_parse
# define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
#endif

#ifndef debug_printf_exec
#define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
#endif

#ifndef debug_printf_env
# define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
#endif

#ifndef debug_printf_jobs
# define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
# define DEBUG_JOBS 1
#else
# define DEBUG_JOBS 0
#endif

#ifndef debug_printf_expand
# define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
# define DEBUG_EXPAND 1
#else
# define DEBUG_EXPAND 0
#endif

#ifndef debug_printf_varexp
# define debug_printf_varexp(...) (indent(), fprintf(stderr, __VA_ARGS__))
#endif

#ifndef debug_printf_glob
# define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
# define DEBUG_GLOB 1
#else
# define DEBUG_GLOB 0
#endif

#ifndef debug_printf_list
# define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
#endif

#ifndef debug_printf_subst
# define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
#endif

#ifndef debug_printf_clean
# define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
# define DEBUG_CLEAN 1
#else
# define DEBUG_CLEAN 0
#endif

#if DEBUG_EXPAND
static void debug_print_strings(const char *prefix, char **vv)
{
	indent();
	fprintf(stderr, "%s:\n", prefix);
	while (*vv)
		fprintf(stderr, " '%s'\n", *vv++);
}
#else
# define debug_print_strings(prefix, vv) ((void)0)
#endif


/* Leak hunting. Use hush_leaktool.sh for post-processing.
 */
#if LEAK_HUNTING
static void *xxmalloc(int lineno, size_t size)
{
	void *ptr = xmalloc((size + 0xff) & ~0xff);
	fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
	return ptr;
}
static void *xxrealloc(int lineno, void *ptr, size_t size)
{
	ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
	fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
	return ptr;
}
static char *xxstrdup(int lineno, const char *str)
{
	char *ptr = xstrdup(str);
	fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
	return ptr;
}
static void xxfree(void *ptr)
{
	fdprintf(2, "free %p\n", ptr);
	free(ptr);
}
# define xmalloc(s)     xxmalloc(__LINE__, s)
# define xrealloc(p, s) xxrealloc(__LINE__, p, s)
# define xstrdup(s)     xxstrdup(__LINE__, s)
# define free(p)        xxfree(p)
#endif


/* Syntax and runtime errors. They always abort scripts.
 * In interactive use they usually discard unparsed and/or unexecuted commands
 * and return to the prompt.
 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
 */
#if HUSH_DEBUG < 2
# define die_if_script(lineno, ...)             die_if_script(__VA_ARGS__)
# define syntax_error(lineno, msg)              syntax_error(msg)
# define syntax_error_at(lineno, msg)           syntax_error_at(msg)
# define syntax_error_unterm_ch(lineno, ch)     syntax_error_unterm_ch(ch)
# define syntax_error_unterm_str(lineno, s)     syntax_error_unterm_str(s)
# define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
#endif

static void die_if_script(unsigned lineno, const char *fmt, ...)
{
	va_list p;

#if HUSH_DEBUG >= 2
	bb_error_msg("hush.c:%u", lineno);
#endif
	va_start(p, fmt);
	bb_verror_msg(fmt, p, NULL);
	va_end(p);
	if (!G_interactive_fd)
		xfunc_die();
}

static void syntax_error(unsigned lineno, const char *msg)
{
	if (msg)
		die_if_script(lineno, "syntax error: %s", msg);
	else
		die_if_script(lineno, "syntax error", NULL);
}

static void syntax_error_at(unsigned lineno, const char *msg)
{
	die_if_script(lineno, "syntax error at '%s'", msg);
}

static void syntax_error_unterm_str(unsigned lineno, const char *s)
{
	die_if_script(lineno, "syntax error: unterminated %s", s);
}

/* It so happens that all such cases are totally fatal
 * even if shell is interactive: EOF while looking for closing
 * delimiter. There is nowhere to read stuff from after that,
 * it's EOF! The only choice is to terminate.
 */
static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
static void syntax_error_unterm_ch(unsigned lineno, char ch)
{
	char msg[2] = { ch, '\0' };
	syntax_error_unterm_str(lineno, msg);
	xfunc_die();
}

static void syntax_error_unexpected_ch(unsigned lineno, int ch)
{
	char msg[2];
	msg[0] = ch;
	msg[1] = '\0';
	die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
}

#if HUSH_DEBUG < 2
# undef die_if_script
# undef syntax_error
# undef syntax_error_at
# undef syntax_error_unterm_ch
# undef syntax_error_unterm_str
# undef syntax_error_unexpected_ch
#else
# define die_if_script(...)             die_if_script(__LINE__, __VA_ARGS__)
# define syntax_error(msg)              syntax_error(__LINE__, msg)
# define syntax_error_at(msg)           syntax_error_at(__LINE__, msg)
# define syntax_error_unterm_ch(ch)     syntax_error_unterm_ch(__LINE__, ch)
# define syntax_error_unterm_str(s)     syntax_error_unterm_str(__LINE__, s)
# define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
#endif


#if ENABLE_HUSH_INTERACTIVE
static void cmdedit_update_prompt(void);
#else
# define cmdedit_update_prompt() ((void)0)
#endif


/* Utility functions
 */
/* Replace each \x with x in place, return ptr past NUL. */
static char *unbackslash(char *src)
{
	char *dst = src = strchrnul(src, '\\');
	while (1) {
		if (*src == '\\')
			src++;
		if ((*dst++ = *src++) == '\0')
			break;
	}
	return dst;
}

static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
{
	int i;
	unsigned count1;
	unsigned count2;
	char **v;

	v = strings;
	count1 = 0;
	if (v) {
		while (*v) {
			count1++;
			v++;
		}
	}
	count2 = 0;
	v = add;
	while (*v) {
		count2++;
		v++;
	}
	v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
	v[count1 + count2] = NULL;
	i = count2;
	while (--i >= 0)
		v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
	return v;
}
#if LEAK_HUNTING
static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
{
	char **ptr = add_strings_to_strings(strings, add, need_to_dup);
	fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
	return ptr;
}
#define add_strings_to_strings(strings, add, need_to_dup) \
	xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
#endif

/* Note: takes ownership of "add" ptr (it is not strdup'ed) */
static char **add_string_to_strings(char **strings, char *add)
{
	char *v[2];
	v[0] = add;
	v[1] = NULL;
	return add_strings_to_strings(strings, v, /*dup:*/ 0);
}
#if LEAK_HUNTING
static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
{
	char **ptr = add_string_to_strings(strings, add);
	fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
	return ptr;
}
#define add_string_to_strings(strings, add) \
	xx_add_string_to_strings(__LINE__, strings, add)
#endif

static void free_strings(char **strings)
{
	char **v;

	if (!strings)
		return;
	v = strings;
	while (*v) {
		free(*v);
		v++;
	}
	free(strings);
}


/* Helpers for setting new $n and restoring them back
 */
typedef struct save_arg_t {
	char *sv_argv0;
	char **sv_g_argv;
	int sv_g_argc;
	smallint sv_g_malloced;
} save_arg_t;

static void save_and_replace_G_args(save_arg_t *sv, char **argv)
{
	int n;

	sv->sv_argv0 = argv[0];
	sv->sv_g_argv = G.global_argv;
	sv->sv_g_argc = G.global_argc;
	sv->sv_g_malloced = G.global_args_malloced;

	argv[0] = G.global_argv[0]; /* retain $0 */
	G.global_argv = argv;
	G.global_args_malloced = 0;

	n = 1;
	while (*++argv)
		n++;
	G.global_argc = n;
}

static void restore_G_args(save_arg_t *sv, char **argv)
{
	char **pp;

	if (G.global_args_malloced) {
		/* someone ran "set -- arg1 arg2 ...", undo */
		pp = G.global_argv;
		while (*++pp) /* note: does not free $0 */
			free(*pp);
		free(G.global_argv);
	}
	argv[0] = sv->sv_argv0;
	G.global_argv = sv->sv_g_argv;
	G.global_argc = sv->sv_g_argc;
	G.global_args_malloced = sv->sv_g_malloced;
}


/* Basic theory of signal handling in shell
 * ========================================
 * This does not describe what hush does, rather, it is current understanding
 * what it _should_ do. If it doesn't, it's a bug.
 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
 *
 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
 * is finished or backgrounded. It is the same in interactive and
 * non-interactive shells, and is the same regardless of whether
 * a user trap handler is installed or a shell special one is in effect.
 * ^C or ^Z from keyboard seems to execute "at once" because it usually
 * backgrounds (i.e. stops) or kills all members of currently running
 * pipe.
 *
 * Wait builtin in interruptible by signals for which user trap is set
 * or by SIGINT in interactive shell.
 *
 * Trap handlers will execute even within trap handlers. (right?)
 *
 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
 * except for handlers set to '' (empty string).
 *
 * If job control is off, backgrounded commands ("cmd &")
 * have SIGINT, SIGQUIT set to SIG_IGN.
 *
 * Commands which are run in command substitution ("`cmd`")
 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
 *
 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
 * by the shell from its parent.
 *
 * Signals which differ from SIG_DFL action
 * (note: child (i.e., [v]forked) shell is not an interactive shell):
 *
 * SIGQUIT: ignore
 * SIGTERM (interactive): ignore
 * SIGHUP (interactive):
 *    send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
 *    Note that ^Z is handled not by trapping SIGTSTP, but by seeing
 *    that all pipe members are stopped. Try this in bash:
 *    while :; do :; done - ^Z does not background it
 *    (while :; do :; done) - ^Z backgrounds it
 * SIGINT (interactive): wait for last pipe, ignore the rest
 *    of the command line, show prompt. NB: ^C does not send SIGINT
 *    to interactive shell while shell is waiting for a pipe,
 *    since shell is bg'ed (is not in foreground process group).
 *    Example 1: this waits 5 sec, but does not execute ls:
 *    "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
 *    Example 2: this does not wait and does not execute ls:
 *    "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
 *    Example 3: this does not wait 5 sec, but executes ls:
 *    "sleep 5; ls -l" + press ^C
 *
 * (What happens to signals which are IGN on shell start?)
 * (What happens with signal mask on shell start?)
 *
 * Implementation in hush
 * ======================
 * We use in-kernel pending signal mask to determine which signals were sent.
 * We block all signals which we don't want to take action immediately,
 * i.e. we block all signals which need to have special handling as described
 * above, and all signals which have traps set.
 * After each pipe execution, we extract any pending signals via sigtimedwait()
 * and act on them.
 *
 * unsigned non_DFL_mask: a mask of such "special" signals
 * sigset_t blocked_set:  current blocked signal set
 *
 * "trap - SIGxxx":
 *    clear bit in blocked_set unless it is also in non_DFL_mask
 * "trap 'cmd' SIGxxx":
 *    set bit in blocked_set (even if 'cmd' is '')
 * after [v]fork, if we plan to be a shell:
 *    unblock signals with special interactive handling
 *    (child shell is not interactive),
 *    unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
 * after [v]fork, if we plan to exec:
 *    POSIX says fork clears pending signal mask in child - no need to clear it.
 *    Restore blocked signal set to one inherited by shell just prior to exec.
 *
 * Note: as a result, we do not use signal handlers much. The only uses
 * are to count SIGCHLDs
 * and to restore tty pgrp on signal-induced exit.
 *
 * Note 2 (compat):
 * Standard says "When a subshell is entered, traps that are not being ignored
 * are set to the default actions". bash interprets it so that traps which
 * are set to '' (ignore) are NOT reset to defaults. We do the same.
 */
enum {
	SPECIAL_INTERACTIVE_SIGS = 0
		| (1 << SIGTERM)
		| (1 << SIGINT)
		| (1 << SIGHUP)
		,
	SPECIAL_JOB_SIGS = 0
#if ENABLE_HUSH_JOB
		| (1 << SIGTTIN)
		| (1 << SIGTTOU)
		| (1 << SIGTSTP)
#endif
};

#if ENABLE_HUSH_FAST
static void SIGCHLD_handler(int sig UNUSED_PARAM)
{
	G.count_SIGCHLD++;
//bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
}
#endif

#if ENABLE_HUSH_JOB

/* After [v]fork, in child: do not restore tty pgrp on xfunc death */
# define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
/* After [v]fork, in parent: restore tty pgrp on xfunc death */
# define enable_restore_tty_pgrp_on_exit()  (die_sleep = -1)

/* Restores tty foreground process group, and exits.
 * May be called as signal handler for fatal signal
 * (will resend signal to itself, producing correct exit state)
 * or called directly with -EXITCODE.
 * We also call it if xfunc is exiting. */
static void sigexit(int sig) NORETURN;
static void sigexit(int sig)
{
	/* Disable all signals: job control, SIGPIPE, etc. */
	sigprocmask_allsigs(SIG_BLOCK);

	/* Careful: we can end up here after [v]fork. Do not restore
	 * tty pgrp then, only top-level shell process does that */
	if (G_saved_tty_pgrp && getpid() == G.root_pid)
		tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);

	/* Not a signal, just exit */
	if (sig <= 0)
		_exit(- sig);

	kill_myself_with_sig(sig); /* does not return */
}
#else

# define disable_restore_tty_pgrp_on_exit() ((void)0)
# define enable_restore_tty_pgrp_on_exit()  ((void)0)

#endif

/* Restores tty foreground process group, and exits. */
static void hush_exit(int exitcode) NORETURN;
static void hush_exit(int exitcode)
{
	if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
		/* Prevent recursion:
		 * trap "echo Hi; exit" EXIT; exit
		 */
		char *argv[] = { NULL, G.traps[0], NULL };
		G.traps[0] = NULL;
		G.exiting = 1;
		builtin_eval(argv);
		free(argv[1]);
	}

#if ENABLE_HUSH_JOB
	fflush_all();
	sigexit(- (exitcode & 0xff));
#else
	exit(exitcode);
#endif
}

static int check_and_run_traps(int sig)
{
	static const struct timespec zero_timespec;
	smalluint save_rcode;
	int last_sig = 0;

	if (sig)
		goto jump_in;
	while (1) {
		sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
		if (sig <= 0)
			break;
 jump_in:
		last_sig = sig;
		if (G.traps && G.traps[sig]) {
			if (G.traps[sig][0]) {
				/* We have user-defined handler */
				char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
				save_rcode = G.last_exitcode;
				builtin_eval(argv);
				free(argv[1]);
				G.last_exitcode = save_rcode;
			} /* else: "" trap, ignoring signal */
			continue;
		}
		/* not a trap: special action */
		switch (sig) {
#if ENABLE_HUSH_FAST
		case SIGCHLD:
			G.count_SIGCHLD++;
//bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
			break;
#endif
		case SIGINT:
			/* Builtin was ^C'ed, make it look prettier: */
			bb_putchar('\n');
			G.flag_SIGINT = 1;
			break;
#if ENABLE_HUSH_JOB
		case SIGHUP: {
			struct pipe *job;
			/* bash is observed to signal whole process groups,
			 * not individual processes */
			for (job = G.job_list; job; job = job->next) {
				if (job->pgrp <= 0)
					continue;
				debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
				if (kill(- job->pgrp, SIGHUP) == 0)
					kill(- job->pgrp, SIGCONT);
			}
			sigexit(SIGHUP);
		}
#endif
		default: /* ignored: */
			/* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
			break;
		}
	}
	return last_sig;
}


static const char *get_cwd(int force)
{
	if (force || G.cwd == NULL) {
		/* xrealloc_getcwd_or_warn(arg) calls free(arg),
		 * we must not try to free(bb_msg_unknown) */
		if (G.cwd == bb_msg_unknown)
			G.cwd = NULL;
		G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
		if (!G.cwd)
			G.cwd = bb_msg_unknown;
	}
	return G.cwd;
}


/*
 * Shell and environment variable support
 */
static struct variable **get_ptr_to_local_var(const char *name)
{
	struct variable **pp;
	struct variable *cur;
	int len;

	len = strlen(name);
	pp = &G.top_var;
	while ((cur = *pp) != NULL) {
		if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
			return pp;
		pp = &cur->next;
	}
	return NULL;
}

static struct variable *get_local_var(const char *name)
{
	struct variable **pp = get_ptr_to_local_var(name);
	if (pp)
		return *pp;
	return NULL;
}

static const char* FAST_FUNC get_local_var_value(const char *name)
{
	struct variable **pp = get_ptr_to_local_var(name);
	if (pp)
		return strchr((*pp)->varstr, '=') + 1;
	if (strcmp(name, "PPID") == 0)
		return utoa(G.root_ppid);
	// bash compat: UID? EUID?
#if ENABLE_HUSH_RANDOM_SUPPORT
	if (strcmp(name, "RANDOM") == 0) {
		return utoa(next_random(&G.random_gen));
	}
#endif
	return NULL;
}

/* str holds "NAME=VAL" and is expected to be malloced.
 * We take ownership of it.
 * flg_export:
 *  0: do not change export flag
 *     (if creating new variable, flag will be 0)
 *  1: set export flag and putenv the variable
 * -1: clear export flag and unsetenv the variable
 * flg_read_only is set only when we handle -R var=val
 */
#if !BB_MMU && ENABLE_HUSH_LOCAL
/* all params are used */
#elif BB_MMU && ENABLE_HUSH_LOCAL
#define set_local_var(str, flg_export, local_lvl, flg_read_only) \
	set_local_var(str, flg_export, local_lvl)
#elif BB_MMU && !ENABLE_HUSH_LOCAL
#define set_local_var(str, flg_export, local_lvl, flg_read_only) \
	set_local_var(str, flg_export)
#elif !BB_MMU && !ENABLE_HUSH_LOCAL
#define set_local_var(str, flg_export, local_lvl, flg_read_only) \
	set_local_var(str, flg_export, flg_read_only)
#endif
static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
{
	struct variable **var_pp;
	struct variable *cur;
	char *eq_sign;
	int name_len;

	eq_sign = strchr(str, '=');
	if (!eq_sign) { /* not expected to ever happen? */
		free(str);
		return -1;
	}

	name_len = eq_sign - str + 1; /* including '=' */
	var_pp = &G.top_var;
	while ((cur = *var_pp) != NULL) {
		if (strncmp(cur->varstr, str, name_len) != 0) {
			var_pp = &cur->next;
			continue;
		}
		/* We found an existing var with this name */
		if (cur->flg_read_only) {
#if !BB_MMU
			if (!flg_read_only)
#endif
				bb_error_msg("%s: readonly variable", str);
			free(str);
			return -1;
		}
		if (flg_export == -1) { // "&& cur->flg_export" ?
			debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
			*eq_sign = '\0';
			unsetenv(str);
			*eq_sign = '=';
		}
#if ENABLE_HUSH_LOCAL
		if (cur->func_nest_level < local_lvl) {
			/* New variable is declared as local,
			 * and existing one is global, or local
			 * from enclosing function.
			 * Remove and save old one: */
			*var_pp = cur->next;
			cur->next = *G.shadowed_vars_pp;
			*G.shadowed_vars_pp = cur;
			/* bash 3.2.33(1) and exported vars:
			 * # export z=z
			 * # f() { local z=a; env | grep ^z; }
			 * # f
			 * z=a
			 * # env | grep ^z
			 * z=z
			 */
			if (cur->flg_export)
				flg_export = 1;
			break;
		}
#endif
		if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
 free_and_exp:
			free(str);
			goto exp;
		}
		if (cur->max_len != 0) {
			if (cur->max_len >= strlen(str)) {
				/* This one is from startup env, reuse space */
				strcpy(cur->varstr, str);
				goto free_and_exp;
			}
		} else {
			/* max_len == 0 signifies "malloced" var, which we can
			 * (and has to) free */
			free(cur->varstr);
		}
		cur->max_len = 0;
		goto set_str_and_exp;
	}

	/* Not found - create new variable struct */
	cur = xzalloc(sizeof(*cur));
#if ENABLE_HUSH_LOCAL
	cur->func_nest_level = local_lvl;
#endif
	cur->next = *var_pp;
	*var_pp = cur;

 set_str_and_exp:
	cur->varstr = str;
#if !BB_MMU
	cur->flg_read_only = flg_read_only;
#endif
 exp:
	if (flg_export == 1)
		cur->flg_export = 1;
	if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
		cmdedit_update_prompt();
	if (cur->flg_export) {
		if (flg_export == -1) {
			cur->flg_export = 0;
			/* unsetenv was already done */
		} else {
			debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
			return putenv(cur->varstr);
		}
	}
	return 0;
}

/* Used at startup and after each cd */
static void set_pwd_var(int exp)
{
	set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
		/*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
}

static int unset_local_var_len(const char *name, int name_len)
{
	struct variable *cur;
	struct variable **var_pp;

	if (!name)
		return EXIT_SUCCESS;
	var_pp = &G.top_var;
	while ((cur = *var_pp) != NULL) {
		if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
			if (cur->flg_read_only) {
				bb_error_msg("%s: readonly variable", name);
				return EXIT_FAILURE;
			}
			*var_pp = cur->next;
			debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
			bb_unsetenv(cur->varstr);
			if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
				cmdedit_update_prompt();
			if (!cur->max_len)
				free(cur->varstr);
			free(cur);
			return EXIT_SUCCESS;
		}
		var_pp = &cur->next;
	}
	return EXIT_SUCCESS;
}

static int unset_local_var(const char *name)
{
	return unset_local_var_len(name, strlen(name));
}

static void unset_vars(char **strings)
{
	char **v;

	if (!strings)
		return;
	v = strings;
	while (*v) {
		const char *eq = strchrnul(*v, '=');
		unset_local_var_len(*v, (int)(eq - *v));
		v++;
	}
	free(strings);
}

#if ENABLE_SH_MATH_SUPPORT
# define is_name(c)      ((c) == '_' || isalpha((unsigned char)(c)))
# define is_in_name(c)   ((c) == '_' || isalnum((unsigned char)(c)))
static char* FAST_FUNC 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;
}
#endif

static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
{
	char *var = xasprintf("%s=%s", name, val);
	set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
}


/*
 * Helpers for "var1=val1 var2=val2 cmd" feature
 */
static void add_vars(struct variable *var)
{
	struct variable *next;

	while (var) {
		next = var->next;
		var->next = G.top_var;
		G.top_var = var;
		if (var->flg_export) {
			debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
			putenv(var->varstr);
		} else {
			debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
		}
		var = next;
	}
}

static struct variable *set_vars_and_save_old(char **strings)
{
	char **s;
	struct variable *old = NULL;

	if (!strings)
		return old;
	s = strings;
	while (*s) {
		struct variable *var_p;
		struct variable **var_pp;
		char *eq;

		eq = strchr(*s, '=');
		if (eq) {
			*eq = '\0';
			var_pp = get_ptr_to_local_var(*s);
			*eq = '=';
			if (var_pp) {
				/* Remove variable from global linked list */
				var_p = *var_pp;
				debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
				*var_pp = var_p->next;
				/* Add it to returned list */
				var_p->next = old;
				old = var_p;
			}
			set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
		}
		s++;
	}
	return old;
}


/*
 * in_str support
 */
static int FAST_FUNC static_get(struct in_str *i)
{
	int ch = *i->p;
	if (ch != '\0') {
		i->p++;
		return ch;
	}
	return EOF;
}

static int FAST_FUNC static_peek(struct in_str *i)
{
	return *i->p;
}

#if ENABLE_HUSH_INTERACTIVE

static void cmdedit_update_prompt(void)
{
	if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
		G.PS1 = get_local_var_value("PS1");
		if (G.PS1 == NULL)
			G.PS1 = "\\w \\$ ";
		G.PS2 = get_local_var_value("PS2");
	} else {
		G.PS1 = NULL;
	}
	if (G.PS2 == NULL)
		G.PS2 = "> ";
}

static const char* setup_prompt_string(int promptmode)
{
	const char *prompt_str;
	debug_printf("setup_prompt_string %d ", promptmode);
	if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
		/* Set up the prompt */
		if (promptmode == 0) { /* PS1 */
			free((char*)G.PS1);
			/* bash uses $PWD value, even if it is set by user.
			 * It uses current dir only if PWD is unset.
			 * We always use current dir. */
			G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
			prompt_str = G.PS1;
		} else
			prompt_str = G.PS2;
	} else
		prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
	debug_printf("result '%s'\n", prompt_str);
	return prompt_str;
}

static void get_user_input(struct in_str *i)
{
	int r;
	const char *prompt_str;

	prompt_str = setup_prompt_string(i->promptmode);
# if ENABLE_FEATURE_EDITING
	/* Enable command line editing only while a command line
	 * is actually being read */
	do {
		G.flag_SIGINT = 0;
		/* buglet: SIGINT will not make new prompt to appear _at once_,
		 * only after <Enter>. (^C will work) */
		r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
		/* catch *SIGINT* etc (^C is handled by read_line_input) */
		check_and_run_traps(0);
	} while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
	i->eof_flag = (r < 0);
	if (i->eof_flag) { /* EOF/error detected */
		G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
		G.user_input_buf[1] = '\0';
	}
# else
	do {
		G.flag_SIGINT = 0;
		fputs(prompt_str, stdout);
		fflush_all();
		G.user_input_buf[0] = r = fgetc(i->file);
		/*G.user_input_buf[1] = '\0'; - already is and never changed */
//do we need check_and_run_traps(0)? (maybe only if stdin)
	} while (G.flag_SIGINT);
	i->eof_flag = (r == EOF);
# endif
	i->p = G.user_input_buf;
}

#endif  /* INTERACTIVE */

/* This is the magic location that prints prompts
 * and gets data back from the user */
static int FAST_FUNC file_get(struct in_str *i)
{
	int ch;

	/* If there is data waiting, eat it up */
	if (i->p && *i->p) {
#if ENABLE_HUSH_INTERACTIVE
 take_cached:
#endif
		ch = *i->p++;
		if (i->eof_flag && !*i->p)
			ch = EOF;
		/* note: ch is never NUL */
	} else {
		/* need to double check i->file because we might be doing something
		 * more complicated by now, like sourcing or substituting. */
#if ENABLE_HUSH_INTERACTIVE
		if (G_interactive_fd && i->promptme && i->file == stdin) {
			do {
				get_user_input(i);
			} while (!*i->p); /* need non-empty line */
			i->promptmode = 1; /* PS2 */
			i->promptme = 0;
			goto take_cached;
		}
#endif
		do ch = fgetc(i->file); while (ch == '\0');
	}
	debug_printf("file_get: got '%c' %d\n", ch, ch);
#if ENABLE_HUSH_INTERACTIVE
	if (ch == '\n')
		i->promptme = 1;
#endif
	return ch;
}

/* All callers guarantee this routine will never
 * be used right after a newline, so prompting is not needed.
 */
static int FAST_FUNC file_peek(struct in_str *i)
{
	int ch;
	if (i->p && *i->p) {
		if (i->eof_flag && !i->p[1])
			return EOF;
		return *i->p;
		/* note: ch is never NUL */
	}
	do ch = fgetc(i->file); while (ch == '\0');
	i->eof_flag = (ch == EOF);
	i->peek_buf[0] = ch;
	i->peek_buf[1] = '\0';
	i->p = i->peek_buf;
	debug_printf("file_peek: got '%c' %d\n", ch, ch);
	return ch;
}

static void setup_file_in_str(struct in_str *i, FILE *f)
{
	i->peek = file_peek;
	i->get = file_get;
#if ENABLE_HUSH_INTERACTIVE
	i->promptme = 1;
	i->promptmode = 0; /* PS1 */
#endif
	i->file = f;
	i->p = NULL;
}

static void setup_string_in_str(struct in_str *i, const char *s)
{
	i->peek = static_peek;
	i->get = static_get;
#if ENABLE_HUSH_INTERACTIVE
	i->promptme = 1;
	i->promptmode = 0; /* PS1 */
#endif
	i->p = s;
	i->eof_flag = 0;
}


/*
 * o_string support
 */
#define B_CHUNK  (32 * sizeof(char*))

static void o_reset_to_empty_unquoted(o_string *o)
{
	o->length = 0;
	o->o_quoted = 0;
	if (o->data)
		o->data[0] = '\0';
}

static void o_free(o_string *o)
{
	free(o->data);
	memset(o, 0, sizeof(*o));
}

static ALWAYS_INLINE void o_free_unsafe(o_string *o)
{
	free(o->data);
}

static void o_grow_by(o_string *o, int len)
{
	if (o->length + len > o->maxlen) {
		o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
		o->data = xrealloc(o->data, 1 + o->maxlen);
	}
}

static void o_addchr(o_string *o, int ch)
{
	debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
	o_grow_by(o, 1);
	o->data[o->length] = ch;
	o->length++;
	o->data[o->length] = '\0';
}

static void o_addblock(o_string *o, const char *str, int len)
{
	o_grow_by(o, len);
	memcpy(&o->data[o->length], str, len);
	o->length += len;
	o->data[o->length] = '\0';
}

static void o_addstr(o_string *o, const char *str)
{
	o_addblock(o, str, strlen(str));
}

#if !BB_MMU
static void nommu_addchr(o_string *o, int ch)
{
	if (o)
		o_addchr(o, ch);
}
#else
# define nommu_addchr(o, str) ((void)0)
#endif

static void o_addstr_with_NUL(o_string *o, const char *str)
{
	o_addblock(o, str, strlen(str) + 1);
}

static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
{
	while (len) {
		o_addchr(o, *str);
		if (*str++ == '\\'
		 && (*str != '*' && *str != '?' && *str != '[')
		) {
			o_addchr(o, '\\');
		}
		len--;
	}
}

#undef HUSH_BRACE_EXP
/*
 * HUSH_BRACE_EXP code needs corresponding quoting on variable expansion side.
 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
 * Apparently, on unquoted $v bash still does globbing
 * ("v='*.txt'; echo $v" prints all .txt files),
 * but NOT brace expansion! Thus, there should be TWO independent
 * quoting mechanisms on $v expansion side: one protects
 * $v from brace expansion, and other additionally protects "$v" against globbing.
 * We have only second one.
 */

#ifdef HUSH_BRACE_EXP
# define MAYBE_BRACES "{}"
#else
# define MAYBE_BRACES ""
#endif

/* My analysis of quoting semantics tells me that state information
 * is associated with a destination, not a source.
 */
static void o_addqchr(o_string *o, int ch)
{
	int sz = 1;
	char *found = strchr("*?[\\" MAYBE_BRACES, ch);
	if (found)
		sz++;
	o_grow_by(o, sz);
	if (found) {
		o->data[o->length] = '\\';
		o->length++;
	}
	o->data[o->length] = ch;
	o->length++;
	o->data[o->length] = '\0';
}

static void o_addQchr(o_string *o, int ch)
{
	int sz = 1;
	if (o->o_escape && strchr("*?[\\" MAYBE_BRACES, ch)) {
		sz++;
		o->data[o->length] = '\\';
		o->length++;
	}
	o_grow_by(o, sz);
	o->data[o->length] = ch;
	o->length++;
	o->data[o->length] = '\0';
}

static void o_addQstr(o_string *o, const char *str, int len)
{
	if (!o->o_escape) {
		o_addblock(o, str, len);
		return;
	}
	while (len) {
		char ch;
		int sz;
		int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
		if (ordinary_cnt > len) /* paranoia */
			ordinary_cnt = len;
		o_addblock(o, str, ordinary_cnt);
		if (ordinary_cnt == len)
			return;
		str += ordinary_cnt;
		len -= ordinary_cnt + 1; /* we are processing + 1 char below */

		ch = *str++;
		sz = 1;
		if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
			sz++;
			o->data[o->length] = '\\';
			o->length++;
		}
		o_grow_by(o, sz);
		o->data[o->length] = ch;
		o->length++;
		o->data[o->length] = '\0';
	}
}

/* A special kind of o_string for $VAR and `cmd` expansion.
 * It contains char* list[] at the beginning, which is grown in 16 element
 * increments. Actual string data starts at the next multiple of 16 * (char*).
 * list[i] contains an INDEX (int!) into this string data.
 * It means that if list[] needs to grow, data needs to be moved higher up
 * but list[i]'s need not be modified.
 * NB: remembering how many list[i]'s you have there is crucial.
 * o_finalize_list() operation post-processes this structure - calculates
 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
 */
#if DEBUG_EXPAND || DEBUG_GLOB
static void debug_print_list(const char *prefix, o_string *o, int n)
{
	char **list = (char**)o->data;
	int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
	int i = 0;

	indent();
	fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
			prefix, list, n, string_start, o->length, o->maxlen);
	while (i < n) {
		indent();
		fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
				o->data + (int)list[i] + string_start,
				o->data + (int)list[i] + string_start);
		i++;
	}
	if (n) {
		const char *p = o->data + (int)list[n - 1] + string_start;
		indent();
		fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
	}
}
#else
# define debug_print_list(prefix, o, n) ((void)0)
#endif

/* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
 * in list[n] so that it points past last stored byte so far.
 * It returns n+1. */
static int o_save_ptr_helper(o_string *o, int n)
{
	char **list = (char**)o->data;
	int string_start;
	int string_len;

	if (!o->has_empty_slot) {
		string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
		string_len = o->length - string_start;
		if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
			debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
			/* list[n] points to string_start, make space for 16 more pointers */
			o->maxlen += 0x10 * sizeof(list[0]);
			o->data = xrealloc(o->data, o->maxlen + 1);
			list = (char**)o->data;
			memmove(list + n + 0x10, list + n, string_len);
			o->length += 0x10 * sizeof(list[0]);
		} else {
			debug_printf_list("list[%d]=%d string_start=%d\n",
					n, string_len, string_start);
		}
	} else {
		/* We have empty slot at list[n], reuse without growth */
		string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
		string_len = o->length - string_start;
		debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
				n, string_len, string_start);
		o->has_empty_slot = 0;
	}
	list[n] = (char*)(ptrdiff_t)string_len;
	return n + 1;
}

/* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
static int o_get_last_ptr(o_string *o, int n)
{
	char **list = (char**)o->data;
	int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);

	return ((int)(ptrdiff_t)list[n-1]) + string_start;
}

#ifdef HUSH_BRACE_EXP
/* There in a GNU extension, GLOB_BRACE, but it is not usable:
 * first, it processes even {a} (no commas), second,
 * I didn't manage to make it return strings when they don't match
 * existing files. Need to re-implement it.
 */

/* Helper */
static int glob_needed(const char *s)
{
	while (*s) {
		if (*s == '\\') {
			if (!s[1])
				return 0;
			s += 2;
			continue;
		}
		if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
			return 1;
		s++;
	}
	return 0;
}
/* Return pointer to next closing brace or to comma */
static const char *next_brace_sub(const char *cp)
{
	unsigned depth = 0;
	cp++;
	while (*cp != '\0') {
		if (*cp == '\\') {
			if (*++cp == '\0')
				break;
			cp++;
			continue;
		}
		 /*{*/ if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
			break;
		if (*cp++ == '{') /*}*/
			depth++;
	}

	return *cp != '\0' ? cp : NULL;
}
/* Recursive brace globber. Note: may garble pattern[]. */
static int glob_brace(char *pattern, o_string *o, int n)
{
	char *new_pattern_buf;
	const char *begin;
	const char *next;
	const char *rest;
	const char *p;
	size_t rest_len;

	debug_printf_glob("glob_brace('%s')\n", pattern);

	begin = pattern;
	while (1) {
		if (*begin == '\0')
			goto simple_glob;
		if (*begin == '{') /*}*/ {
			/* Find the first sub-pattern and at the same time
			 * find the rest after the closing brace */
			next = next_brace_sub(begin);
			if (next == NULL) {
				/* An illegal expression */
				goto simple_glob;
			}
			/*{*/ if (*next == '}') {
				/* "{abc}" with no commas - illegal
				 * brace expr, disregard and skip it */
				begin = next + 1;
				continue;
			}
			break;
		}
		if (*begin == '\\' && begin[1] != '\0')
			begin++;
		begin++;
	}
	debug_printf_glob("begin:%s\n", begin);
	debug_printf_glob("next:%s\n", next);

	/* Now find the end of the whole brace expression */
	rest = next;
	/*{*/ while (*rest != '}') {
		rest = next_brace_sub(rest);
		if (rest == NULL) {
			/* An illegal expression */
			goto simple_glob;
		}
		debug_printf_glob("rest:%s\n", rest);
	}
	rest_len = strlen(++rest) + 1;

	/* We are sure the brace expression is well-formed */

	/* Allocate working buffer large enough for our work */
	new_pattern_buf = xmalloc(strlen(pattern));

	/* We have a brace expression.  BEGIN points to the opening {,
	 * NEXT points past the terminator of the first element, and REST
	 * points past the final }.  We will accumulate result names from
	 * recursive runs for each brace alternative in the buffer using
	 * GLOB_APPEND.  */

	p = begin + 1;
	while (1) {
		/* Construct the new glob expression */
		memcpy(
			mempcpy(
				mempcpy(new_pattern_buf,
					/* We know the prefix for all sub-patterns */
					pattern, begin - pattern),
				p, next - p),
			rest, rest_len);

		/* Note: glob_brace() may garble new_pattern_buf[].
		 * That's why we re-copy prefix every time (1st memcpy above).
		 */
		n = glob_brace(new_pattern_buf, o, n);
		/*{*/ if (*next == '}') {
			/* We saw the last entry */
			break;
		}
		p = next + 1;
		next = next_brace_sub(next);
	}
	free(new_pattern_buf);
	return n;

 simple_glob:
	{
		int gr;
		glob_t globdata;

		memset(&globdata, 0, sizeof(globdata));
		gr = glob(pattern, 0, NULL, &globdata);
		debug_printf_glob("glob('%s'):%d\n", pattern, gr);
		if (gr != 0) {
			if (gr == GLOB_NOMATCH) {
				globfree(&globdata);
				/* NB: garbles parameter */
				unbackslash(pattern);
				o_addstr_with_NUL(o, pattern);
				debug_printf_glob("glob pattern '%s' is literal\n", pattern);
				return o_save_ptr_helper(o, n);
			}
			if (gr == GLOB_NOSPACE)
				bb_error_msg_and_die(bb_msg_memory_exhausted);
			/* GLOB_ABORTED? Only happens with GLOB_ERR flag,
			 * but we didn't specify it. Paranoia again. */
			bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
		}
		if (globdata.gl_pathv && globdata.gl_pathv[0]) {
			char **argv = globdata.gl_pathv;
			while (1) {
				o_addstr_with_NUL(o, *argv);
				n = o_save_ptr_helper(o, n);
				argv++;
				if (!*argv)
					break;
			}
		}
		globfree(&globdata);
	}
	return n;
}
/* Performs globbing on last list[],
 * saving each result as a new list[].
 */
static int o_glob(o_string *o, int n)
{
	char *pattern, *copy;

	debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
	if (!o->data)
		return o_save_ptr_helper(o, n);
	pattern = o->data + o_get_last_ptr(o, n);
	debug_printf_glob("glob pattern '%s'\n", pattern);
	if (!glob_needed(pattern)) {
		/* unbackslash last string in o in place, fix length */
		o->length = unbackslash(pattern) - o->data;
		debug_printf_glob("glob pattern '%s' is literal\n", pattern);
		return o_save_ptr_helper(o, n);
	}

	copy = xstrdup(pattern);
	/* "forget" pattern in o */
	o->length = pattern - o->data;
	n = glob_brace(copy, o, n);
	free(copy);
	if (DEBUG_GLOB)
		debug_print_list("o_glob returning", o, n);
	return n;
}

#else /* !HUSH_BRACE_EXP */

/* Helper */
static int glob_needed(const char *s)
{
	while (*s) {
		if (*s == '\\') {
			if (!s[1])
				return 0;
			s += 2;
			continue;
		}
		if (*s == '*' || *s == '[' || *s == '?')
			return 1;
		s++;
	}
	return 0;
}
/* Performs globbing on last list[],
 * saving each result as a new list[].
 */
static int o_glob(o_string *o, int n)
{
	glob_t globdata;
	int gr;
	char *pattern;

	debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
	if (!o->data)
		return o_save_ptr_helper(o, n);
	pattern = o->data + o_get_last_ptr(o, n);
	debug_printf_glob("glob pattern '%s'\n", pattern);
	if (!glob_needed(pattern)) {
 literal:
		/* unbackslash last string in o in place, fix length */
		o->length = unbackslash(pattern) - o->data;
		debug_printf_glob("glob pattern '%s' is literal\n", pattern);
		return o_save_ptr_helper(o, n);
	}

	memset(&globdata, 0, sizeof(globdata));
	/* Can't use GLOB_NOCHECK: it does not unescape the string.
	 * If we glob "*.\*" and don't find anything, we need
	 * to fall back to using literal "*.*", but GLOB_NOCHECK
	 * will return "*.\*"!
	 */
	gr = glob(pattern, 0, NULL, &globdata);
	debug_printf_glob("glob('%s'):%d\n", pattern, gr);
	if (gr != 0) {
		if (gr == GLOB_NOMATCH) {
			globfree(&globdata);
			goto literal;
		}
		if (gr == GLOB_NOSPACE)
			bb_error_msg_and_die(bb_msg_memory_exhausted);
		/* GLOB_ABORTED? Only happens with GLOB_ERR flag,
		 * but we didn't specify it. Paranoia again. */
		bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
	}
	if (globdata.gl_pathv && globdata.gl_pathv[0]) {
		char **argv = globdata.gl_pathv;
		/* "forget" pattern in o */
		o->length = pattern - o->data;
		while (1) {
			o_addstr_with_NUL(o, *argv);
			n = o_save_ptr_helper(o, n);
			argv++;
			if (!*argv)
				break;
		}
	}
	globfree(&globdata);
	if (DEBUG_GLOB)
		debug_print_list("o_glob returning", o, n);
	return n;
}

#endif /* !HUSH_BRACE_EXP */

/* If o->o_glob == 1, glob the string so far remembered.
 * Otherwise, just finish current list[] and start new */
static int o_save_ptr(o_string *o, int n)
{
	if (o->o_glob) { /* if globbing is requested */
		/* If o->has_empty_slot, list[n] was already globbed
		 * (if it was requested back then when it was filled)
		 * so don't do that again! */
		if (!o->has_empty_slot)
			return o_glob(o, n); /* o_save_ptr_helper is inside */
	}
	return o_save_ptr_helper(o, n);
}

/* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
static char **o_finalize_list(o_string *o, int n)
{
	char **list;
	int string_start;

	n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
	if (DEBUG_EXPAND)
		debug_print_list("finalized", o, n);
	debug_printf_expand("finalized n:%d\n", n);
	list = (char**)o->data;
	string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
	list[--n] = NULL;
	while (n) {
		n--;
		list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
	}
	return list;
}


/* Expansion can recurse */
#if ENABLE_HUSH_TICK
static int process_command_subs(o_string *dest, const char *s);
#endif
static char *expand_string_to_string(const char *str);
#if BB_MMU
#define parse_stream_dquoted(as_string, dest, input, dquote_end) \
	parse_stream_dquoted(dest, input, dquote_end)
#endif
static int parse_stream_dquoted(o_string *as_string,
		o_string *dest,
		struct in_str *input,
		int dquote_end);

/* expand_strvec_to_strvec() takes a list of strings, expands
 * all variable references within and returns a pointer to
 * a list of expanded strings, possibly with larger number
 * of strings. (Think VAR="a b"; echo $VAR).
 * This new list is allocated as a single malloc block.
 * NULL-terminated list of char* pointers is at the beginning of it,
 * followed by strings themself.
 * Caller can deallocate entire list by single free(list). */

/* Store given string, finalizing the word and starting new one whenever
 * we encounter IFS char(s). This is used for expanding variable values.
 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
static int expand_on_ifs(o_string *output, int n, const char *str)
{
	while (1) {
		int word_len = strcspn(str, G.ifs);
		if (word_len) {
			if (output->o_escape || !output->o_glob)
				o_addQstr(output, str, word_len);
			else /* protect backslashes against globbing up :) */
				o_addblock_duplicate_backslash(output, str, word_len);
			str += word_len;
		}
		if (!*str)  /* EOL - do not finalize word */
			break;
		o_addchr(output, '\0');
		debug_print_list("expand_on_ifs", output, n);
		n = o_save_ptr(output, n);
		str += strspn(str, G.ifs); /* skip ifs chars */
	}
	debug_print_list("expand_on_ifs[1]", output, n);
	return n;
}

/* Helper to expand $((...)) and heredoc body. These act as if
 * they are in double quotes, with the exception that they are not :).
 * Just the rules are similar: "expand only $var and `cmd`"
 *
 * Returns malloced string.
 * As an optimization, we return NULL if expansion is not needed.
 */
static char *expand_pseudo_dquoted(const char *str)
{
	char *exp_str;
	struct in_str input;
	o_string dest = NULL_O_STRING;

	if (strchr(str, '$') == NULL
#if ENABLE_HUSH_TICK
	 && strchr(str, '`') == NULL
#endif
	) {
		return NULL;
	}

	/* We need to expand. Example:
	 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
	 */
	setup_string_in_str(&input, str);
	parse_stream_dquoted(NULL, &dest, &input, EOF);
	//bb_error_msg("'%s' -> '%s'", str, dest.data);
	exp_str = expand_string_to_string(dest.data);
	//bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
	o_free_unsafe(&dest);
	return exp_str;
}

#if ENABLE_SH_MATH_SUPPORT
static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
{
	arith_eval_hooks_t hooks;
	arith_t res;
	char *exp_str;

	hooks.lookupvar = get_local_var_value;
	hooks.setvar = set_local_var_from_halves;
	hooks.endofname = endofname;
	exp_str = expand_pseudo_dquoted(arg);
	res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
	free(exp_str);
	return res;
}
#endif

/* Expand all variable references in given string, adding words to list[]
 * at n, n+1,... positions. Return updated n (so that list[n] is next one
 * to be filled). This routine is extremely tricky: has to deal with
 * variables/parameters with whitespace, $* and $@, and constructs like
 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
{
	/* or_mask is either 0 (normal case) or 0x80 -
	 * expansion of right-hand side of assignment == 1-element expand.
	 * It will also do no globbing, and thus we must not backslash-quote!
	 */
	char ored_ch;
	char *p;

	ored_ch = 0;

	debug_printf_expand("expand_vars_to_list: arg:'%s' or_mask:%x\n", arg, or_mask);
	debug_print_list("expand_vars_to_list", output, n);
	n = o_save_ptr(output, n);
	debug_print_list("expand_vars_to_list[0]", output, n);

	while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
		char first_ch;
		int i;
		char *to_be_freed = NULL;
		const char *val = NULL;
#if ENABLE_HUSH_TICK
		o_string subst_result = NULL_O_STRING;
#endif
#if ENABLE_SH_MATH_SUPPORT
		char arith_buf[sizeof(arith_t)*3 + 2];
#endif
		o_addblock(output, arg, p - arg);
		debug_print_list("expand_vars_to_list[1]", output, n);
		arg = ++p;
		p = strchr(p, SPECIAL_VAR_SYMBOL);

		first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
		/* "$@" is special. Even if quoted, it can still
		 * expand to nothing (not even an empty string) */
		if ((first_ch & 0x7f) != '@')
			ored_ch |= first_ch;

		switch (first_ch & 0x7f) {
		/* Highest bit in first_ch indicates that var is double-quoted */
		case '*':
		case '@':
			i = 1;
			if (!G.global_argv[i])
				break;
			ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
			if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
				smallint sv = output->o_escape;
				/* unquoted var's contents should be globbed, so don't escape */
				output->o_escape = 0;
				while (G.global_argv[i]) {
					n = expand_on_ifs(output, n, G.global_argv[i]);
					debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
					if (G.global_argv[i++][0] && G.global_argv[i]) {
						/* this argv[] is not empty and not last:
						 * put terminating NUL, start new word */
						o_addchr(output, '\0');
						debug_print_list("expand_vars_to_list[2]", output, n);
						n = o_save_ptr(output, n);
						debug_print_list("expand_vars_to_list[3]", output, n);
					}
				}
				output->o_escape = sv;
			} else
			/* If or_mask is nonzero, we handle assignment 'a=....$@.....'
			 * and in this case should treat it like '$*' - see 'else...' below */
			if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
				while (1) {
					o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
					if (++i >= G.global_argc)
						break;
					o_addchr(output, '\0');
					debug_print_list("expand_vars_to_list[4]", output, n);
					n = o_save_ptr(output, n);
				}
			} else { /* quoted $*: add as one word */
				while (1) {
					o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
					if (!G.global_argv[++i])
						break;
					if (G.ifs[0])
						o_addchr(output, G.ifs[0]);
				}
			}
			break;
		case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
			/* "Empty variable", used to make "" etc to not disappear */
			arg++;
			ored_ch = 0x80;
			break;
#if ENABLE_HUSH_TICK
		case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
			*p = '\0';
			arg++;
			/* Can't just stuff it into output o_string,
			 * expanded result may need to be globbed
			 * and $IFS-splitted */
			debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
			G.last_exitcode = process_command_subs(&subst_result, arg);
			debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
			val = subst_result.data;
			goto store_val;
#endif
#if ENABLE_SH_MATH_SUPPORT
		case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
			arith_t res;
			int errcode;

			arg++; /* skip '+' */
			*p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
			debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
			res = expand_and_evaluate_arith(arg, &errcode);

			if (errcode < 0) {
				const char *msg = "error in arithmetic";
				switch (errcode) {
				case -3:
					msg = "exponent less than 0";
					break;
				case -2:
					msg = "divide by 0";
					break;
				case -5:
					msg = "expression recursion loop detected";
					break;
				}
				die_if_script(msg);
			}
			debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
			sprintf(arith_buf, arith_t_fmt, res);
			val = arith_buf;
			break;
		}
#endif
		default: { /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
			char *var;
			char first_char;
			char exp_op;
			char exp_save = exp_save; /* for compiler */
			char *exp_saveptr; /* points to expansion operator */
			char *exp_word = exp_word; /* for compiler */

			var = arg;
			*p = '\0';
			exp_saveptr = arg[1] ? strchr("%#:-=+?", arg[1]) : NULL;
			first_char = arg[0] = first_ch & 0x7f;
			exp_op = 0;

			if (first_char == '#' && arg[1] && !exp_saveptr) {
				/* handle length expansion ${#var} */
				var++;
				exp_op = 'L';
			} else {
				/* maybe handle parameter expansion */
				if (exp_saveptr /* if 2nd char is one of expansion operators */
				 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
				) {
					/* ${?:0}, ${#[:]%0} etc */
					exp_saveptr = var + 1;
				} else {
					/* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
					exp_saveptr = var+1 + strcspn(var+1, "%#:-=+?");
				}
				exp_op = exp_save = *exp_saveptr;
				if (exp_op) {
					exp_word = exp_saveptr + 1;
					if (exp_op == ':') {
						exp_op = *exp_word++;
						if (ENABLE_HUSH_BASH_COMPAT
						 && (exp_op == '\0' || !strchr("%#:-=+?"+3, exp_op))
						) {
							/* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
							exp_op = ':';
							exp_word--;
						}
					}
					*exp_saveptr = '\0';
				} /* else: it's not an expansion op, but bare ${var} */
			}

			/* lookup the variable in question */
			if (isdigit(var[0])) {
				/* parse_dollar() should have vetted var for us */
				i = xatoi_u(var);
				if (i < G.global_argc)
					val = G.global_argv[i];
				/* else val remains NULL: $N with too big N */
			} else {
				switch (var[0]) {
				case '$': /* pid */
					val = utoa(G.root_pid);
					break;
				case '!': /* bg pid */
					val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
					break;
				case '?': /* exitcode */
					val = utoa(G.last_exitcode);
					break;
				case '#': /* argc */
					val = utoa(G.global_argc ? G.global_argc-1 : 0);
					break;
				default:
					val = get_local_var_value(var);
				}
			}

			/* handle any expansions */
			if (exp_op == 'L') {
				debug_printf_expand("expand: length(%s)=", val);
				val = utoa(val ? strlen(val) : 0);
				debug_printf_expand("%s\n", val);
			} else if (exp_op) {
				if (exp_op == '%' || exp_op == '#') {
	/* Standard-mandated substring removal ops:
	 * ${parameter%word} - remove smallest suffix pattern
	 * ${parameter%%word} - remove largest suffix pattern
	 * ${parameter#word} - remove smallest prefix pattern
	 * ${parameter##word} - remove largest prefix pattern
	 *
	 * Word is expanded to produce a glob pattern.
	 * Then var's value is matched to it and matching part removed.
	 */
					if (val) {
						bool match_at_left;
						char *loc;
						scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
						if (exp_op == *exp_word)	/* ## or %% */
							exp_word++;
						val = to_be_freed = xstrdup(val);
						{
							char *exp_exp_word = expand_pseudo_dquoted(exp_word);
							if (exp_exp_word)
								exp_word = exp_exp_word;
							loc = scan(to_be_freed, exp_word, match_at_left);
							//bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
							//		exp_op, to_be_freed, exp_word, loc);
							free(exp_exp_word);
						}
						if (loc) { /* match was found */
							if (match_at_left) /* # or ## */
								val = loc;
							else /* % or %% */
								*loc = '\0';
						}
					}
				} else if (exp_op == ':') {
#if ENABLE_HUSH_BASH_COMPAT
	/* It's ${var:N[:M]} bashism.
	 * Note that in encoded form it has TWO parts:
	 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
	 */
					arith_t beg, len;
					int errcode = 0;

					beg = expand_and_evaluate_arith(exp_word, &errcode);
					debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
					*p++ = SPECIAL_VAR_SYMBOL;
					exp_word = p;
					p = strchr(p, SPECIAL_VAR_SYMBOL);
					*p = '\0';
					len = expand_and_evaluate_arith(exp_word, &errcode);
					debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);

					if (errcode >= 0 && len >= 0) { /* bash compat: len < 0 is illegal */
						if (beg < 0) /* bash compat */
							beg = 0;
						debug_printf_varexp("from val:'%s'\n", val);
						if (len == 0 || !val || beg >= strlen(val))
							val = "";
						else {
							/* Paranoia. What if user entered 9999999999999
							 * which fits in arith_t but not int? */
							if (len >= INT_MAX)
								len = INT_MAX;
							val = to_be_freed = xstrndup(val + beg, len);
						}
						debug_printf_varexp("val:'%s'\n", val);
					} else
#endif
					{
						die_if_script("malformed ${%s:...}", var);
						val = "";
					}
				} else { /* one of "-=+?" */
	/* Standard-mandated substitution ops:
	 * ${var?word} - indicate error if unset
	 *      If var is unset, word (or a message indicating it is unset
	 *      if word is null) is written to standard error
	 *      and the shell exits with a non-zero exit status.
	 *      Otherwise, the value of var is substituted.
	 * ${var-word} - use default value
	 *      If var is unset, word is substituted.
	 * ${var=word} - assign and use default value
	 *      If var is unset, word is assigned to var.
	 *      In all cases, final value of var is substituted.
	 * ${var+word} - use alternative value
	 *      If var is unset, null is substituted.
	 *      Otherwise, word is substituted.
	 *
	 * Word is subjected to tilde expansion, parameter expansion,
	 * command substitution, and arithmetic expansion.
	 * If word is not needed, it is not expanded.
	 *
	 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
	 * but also treat null var as if it is unset.
	 */
					int use_word = (!val || ((exp_save == ':') && !val[0]));
					if (exp_op == '+')
						use_word = !use_word;
					debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
						(exp_save == ':') ? "true" : "false", use_word);
					if (use_word) {
						to_be_freed = expand_pseudo_dquoted(exp_word);
						if (to_be_freed)
							exp_word = to_be_freed;
						if (exp_op == '?') {
							/* mimic bash message */
							die_if_script("%s: %s",
								var,
								exp_word[0] ? exp_word : "parameter null or not set"
							);
//TODO: how interactive bash aborts expansion mid-command?
						} else {
							val = exp_word;
						}

						if (exp_op == '=') {
							/* ${var=[word]} or ${var:=[word]} */
							if (isdigit(var[0]) || var[0] == '#') {
								/* mimic bash message */
								die_if_script("$%s: cannot assign in this way", var);
								val = NULL;
							} else {
								char *new_var = xasprintf("%s=%s", var, val);
								set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
							}
						}
					}
				} /* one of "-=+?" */

				*exp_saveptr = exp_save;
			} /* if (exp_op) */

			arg[0] = first_ch;
#if ENABLE_HUSH_TICK
 store_val:
#endif
			if (!(first_ch & 0x80)) { /* unquoted $VAR */
				debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
				if (val) {
					/* unquoted var's contents should be globbed, so don't escape */
					smallint sv = output->o_escape;
					output->o_escape = 0;
					n = expand_on_ifs(output, n, val);
					val = NULL;
					output->o_escape = sv;
				}
			} else { /* quoted $VAR, val will be appended below */
				debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
			}
		} /* default: */
		} /* switch (char after <SPECIAL_VAR_SYMBOL>) */

		if (val) {
			o_addQstr(output, val, strlen(val));
		}
		free(to_be_freed);
		/* Do the check to avoid writing to a const string */
		if (*p != SPECIAL_VAR_SYMBOL)
			*p = SPECIAL_VAR_SYMBOL;

#if ENABLE_HUSH_TICK
		o_free(&subst_result);
#endif
		arg = ++p;
	} /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */

	if (arg[0]) {
		debug_print_list("expand_vars_to_list[a]", output, n);
		/* this part is literal, and it was already pre-quoted
		 * if needed (much earlier), do not use o_addQstr here! */
		o_addstr_with_NUL(output, arg);
		debug_print_list("expand_vars_to_list[b]", output, n);
	} else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
	 && !(ored_ch & 0x80) /* and all vars were not quoted. */
	) {
		n--;
		/* allow to reuse list[n] later without re-growth */
		output->has_empty_slot = 1;
	} else {
		o_addchr(output, '\0');
	}
	return n;
}

static char **expand_variables(char **argv, int or_mask)
{
	int n;
	char **list;
	char **v;
	o_string output = NULL_O_STRING;

	if (or_mask & 0x100) {
		output.o_escape = 1; /* protect against globbing for "$var" */
		/* (unquoted $var will temporarily switch it off) */
		output.o_glob = 1;
	}

	n = 0;
	v = argv;
	while (*v) {
		n = expand_vars_to_list(&output, n, *v, (unsigned char)or_mask);
		v++;
	}
	debug_print_list("expand_variables", &output, n);

	/* output.data (malloced in one block) gets returned in "list" */
	list = o_finalize_list(&output, n);
	debug_print_strings("expand_variables[1]", list);
	return list;
}

static char **expand_strvec_to_strvec(char **argv)
{
	return expand_variables(argv, 0x100);
}

#if ENABLE_HUSH_BASH_COMPAT
static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
{
	return expand_variables(argv, 0x80);
}
#endif

#ifdef CMD_SINGLEWORD_NOGLOB_COND
static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
{
	int n;
	char **list;
	char **v;
	o_string output = NULL_O_STRING;

	n = 0;
	v = argv;
	while (*v) {
		int is_var = is_well_formed_var_name(*v, '=');
		/* is_var * 0x80: singleword expansion for vars */
		n = expand_vars_to_list(&output, n, *v, is_var * 0x80);

		/* Subtle! expand_vars_to_list did not glob last word yet.
		 * It does this only when fed with further data.
		 * Therefore we set globbing flags AFTER it, not before:
		 */

		/* if it is not recognizably abc=...; then: */
		output.o_escape = !is_var; /* protect against globbing for "$var" */
		/* (unquoted $var will temporarily switch it off) */
		output.o_glob = !is_var; /* and indeed do globbing */
		v++;
	}
	debug_print_list("expand_cond", &output, n);

	/* output.data (malloced in one block) gets returned in "list" */
	list = o_finalize_list(&output, n);
	debug_print_strings("expand_cond[1]", list);
	return list;
}
#endif

/* Used for expansion of right hand of assignments */
/* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
 * "v=/bin/c*" */
static char *expand_string_to_string(const char *str)
{
	char *argv[2], **list;

	argv[0] = (char*)str;
	argv[1] = NULL;
	list = expand_variables(argv, 0x80); /* 0x80: singleword expansion */
	if (HUSH_DEBUG)
		if (!list[0] || list[1])
			bb_error_msg_and_die("BUG in varexp2");
	/* actually, just move string 2*sizeof(char*) bytes back */
	overlapping_strcpy((char*)list, list[0]);
	unbackslash((char*)list);
	debug_printf_expand("string_to_string='%s'\n", (char*)list);
	return (char*)list;
}

/* Used for "eval" builtin */
static char* expand_strvec_to_string(char **argv)
{
	char **list;

	list = expand_variables(argv, 0x80);
	/* Convert all NULs to spaces */
	if (list[0]) {
		int n = 1;
		while (list[n]) {
			if (HUSH_DEBUG)
				if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
					bb_error_msg_and_die("BUG in varexp3");
			/* bash uses ' ' regardless of $IFS contents */
			list[n][-1] = ' ';
			n++;
		}
	}
	overlapping_strcpy((char*)list, list[0]);
	debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
	return (char*)list;
}

static char **expand_assignments(char **argv, int count)
{
	int i;
	char **p = NULL;
	/* Expand assignments into one string each */
	for (i = 0; i < count; i++) {
		p = add_string_to_strings(p, expand_string_to_string(argv[i]));
	}
	return p;
}


#if BB_MMU
/* never called */
void re_execute_shell(char ***to_free, const char *s,
		char *g_argv0, char **g_argv,
		char **builtin_argv) NORETURN;

static void reset_traps_to_defaults(void)
{
	/* This function is always called in a child shell
	 * after fork (not vfork, NOMMU doesn't use this function).
	 */
	unsigned sig;
	unsigned mask;

	/* Child shells are not interactive.
	 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
	 * Testcase: (while :; do :; done) + ^Z should background.
	 * Same goes for SIGTERM, SIGHUP, SIGINT.
	 */
	if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
		return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */

	/* Switching off SPECIAL_INTERACTIVE_SIGS.
	 * Stupid. It can be done with *single* &= op, but we can't use
	 * the fact that G.blocked_set is implemented as a bitmask
	 * in libc... */
	mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
	sig = 1;
	while (1) {
		if (mask & 1) {
			/* Careful. Only if no trap or trap is not "" */
			if (!G.traps || !G.traps[sig] || G.traps[sig][0])
				sigdelset(&G.blocked_set, sig);
		}
		mask >>= 1;
		if (!mask)
			break;
		sig++;
	}
	/* Our homegrown sig mask is saner to work with :) */
	G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;

	/* Resetting all traps to default except empty ones */
	mask = G.non_DFL_mask;
	if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
		if (!G.traps[sig] || !G.traps[sig][0])
			continue;
		free(G.traps[sig]);
		G.traps[sig] = NULL;
		/* There is no signal for 0 (EXIT) */
		if (sig == 0)
			continue;
		/* There was a trap handler, we just removed it.
		 * But if sig still has non-DFL handling,
		 * we should not unblock the sig. */
		if (mask & 1)
			continue;
		sigdelset(&G.blocked_set, sig);
	}
	sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
}

#else /* !BB_MMU */

static void re_execute_shell(char ***to_free, const char *s,
		char *g_argv0, char **g_argv,
		char **builtin_argv) NORETURN;
static void re_execute_shell(char ***to_free, const char *s,
		char *g_argv0, char **g_argv,
		char **builtin_argv)
{
# define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
	/* delims + 2 * (number of bytes in printed hex numbers) */
	char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
	char *heredoc_argv[4];
	struct variable *cur;
# if ENABLE_HUSH_FUNCTIONS
	struct function *funcp;
# endif
	char **argv, **pp;
	unsigned cnt;
	unsigned long long empty_trap_mask;

	if (!g_argv0) { /* heredoc */
		argv = heredoc_argv;
		argv[0] = (char *) G.argv0_for_re_execing;
		argv[1] = (char *) "-<";
		argv[2] = (char *) s;
		argv[3] = NULL;
		pp = &argv[3]; /* used as pointer to empty environment */
		goto do_exec;
	}

	cnt = 0;
	pp = builtin_argv;
	if (pp) while (*pp++)
		cnt++;

	empty_trap_mask = 0;
	if (G.traps) {
		int sig;
		for (sig = 1; sig < NSIG; sig++) {
			if (G.traps[sig] && !G.traps[sig][0])
				empty_trap_mask |= 1LL << sig;
		}
	}

	sprintf(param_buf, NOMMU_HACK_FMT
			, (unsigned) G.root_pid
			, (unsigned) G.root_ppid
			, (unsigned) G.last_bg_pid
			, (unsigned) G.last_exitcode
			, cnt
			, empty_trap_mask
			IF_HUSH_LOOPS(, G.depth_of_loop)
			);
# undef NOMMU_HACK_FMT
	/* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
	 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
	 */
	cnt += 6;
	for (cur = G.top_var; cur; cur = cur->next) {
		if (!cur->flg_export || cur->flg_read_only)
			cnt += 2;
	}
# if ENABLE_HUSH_FUNCTIONS
	for (funcp = G.top_func; funcp; funcp = funcp->next)
		cnt += 3;
# endif
	pp = g_argv;
	while (*pp++)
		cnt++;
	*to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
	*pp++ = (char *) G.argv0_for_re_execing;
	*pp++ = param_buf;
	for (cur = G.top_var; cur; cur = cur->next) {
		if (cur->varstr == hush_version_str)
			continue;
		if (cur->flg_read_only) {
			*pp++ = (char *) "-R";
			*pp++ = cur->varstr;
		} else if (!cur->flg_export) {
			*pp++ = (char *) "-V";
			*pp++ = cur->varstr;
		}
	}
# if ENABLE_HUSH_FUNCTIONS
	for (funcp = G.top_func; funcp; funcp = funcp->next) {
		*pp++ = (char *) "-F";
		*pp++ = funcp->name;
		*pp++ = funcp->body_as_string;
	}
# endif
	/* We can pass activated traps here. Say, -Tnn:trap_string
	 *
	 * However, POSIX says that subshells reset signals with traps
	 * to SIG_DFL.
	 * I tested bash-3.2 and it not only does that with true subshells
	 * of the form ( list ), but with any forked children shells.
	 * I set trap "echo W" WINCH; and then tried:
	 *
	 * { echo 1; sleep 20; echo 2; } &
	 * while true; do echo 1; sleep 20; echo 2; break; done &
	 * true | { echo 1; sleep 20; echo 2; } | cat
	 *
	 * In all these cases sending SIGWINCH to the child shell
	 * did not run the trap. If I add trap "echo V" WINCH;
	 * _inside_ group (just before echo 1), it works.
	 *
	 * I conclude it means we don't need to pass active traps here.
	 * Even if we would use signal handlers instead of signal masking
	 * in order to implement trap handling,
	 * exec syscall below resets signals to SIG_DFL for us.
	 */
	*pp++ = (char *) "-c";
	*pp++ = (char *) s;
	if (builtin_argv) {
		while (*++builtin_argv)
			*pp++ = *builtin_argv;
		*pp++ = (char *) "";
	}
	*pp++ = g_argv0;
	while (*g_argv)
		*pp++ = *g_argv++;
	/* *pp = NULL; - is already there */
	pp = environ;

 do_exec:
	debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
	sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
	execve(bb_busybox_exec_path, argv, pp);
	/* Fallback. Useful for init=/bin/hush usage etc */
	if (argv[0][0] == '/')
		execve(argv[0], argv, pp);
	xfunc_error_retval = 127;
	bb_error_msg_and_die("can't re-execute the shell");
}
#endif  /* !BB_MMU */


static void setup_heredoc(struct redir_struct *redir)
{
	struct fd_pair pair;
	pid_t pid;
	int len, written;
	/* the _body_ of heredoc (misleading field name) */
	const char *heredoc = redir->rd_filename;
	char *expanded;
#if !BB_MMU
	char **to_free;
#endif

	expanded = NULL;
	if (!(redir->rd_dup & HEREDOC_QUOTED)) {
		expanded = expand_pseudo_dquoted(heredoc);
		if (expanded)
			heredoc = expanded;
	}
	len = strlen(heredoc);

	close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
	xpiped_pair(pair);
	xmove_fd(pair.rd, redir->rd_fd);

	/* Try writing without forking. Newer kernels have
	 * dynamically growing pipes. Must use non-blocking write! */
	ndelay_on(pair.wr);
	while (1) {
		written = write(pair.wr, heredoc, len);
		if (written <= 0)
			break;
		len -= written;
		if (len == 0) {
			close(pair.wr);
			free(expanded);
			return;
		}
		heredoc += written;
	}
	ndelay_off(pair.wr);

	/* Okay, pipe buffer was not big enough */
	/* Note: we must not create a stray child (bastard? :)
	 * for the unsuspecting parent process. Child creates a grandchild
	 * and exits before parent execs the process which consumes heredoc
	 * (that exec happens after we return from this function) */
#if !BB_MMU
	to_free = NULL;
#endif
	pid = xvfork();
	if (pid == 0) {
		/* child */
		disable_restore_tty_pgrp_on_exit();
		pid = BB_MMU ? xfork() : xvfork();
		if (pid != 0)
			_exit(0);
		/* grandchild */
		close(redir->rd_fd); /* read side of the pipe */
#if BB_MMU
		full_write(pair.wr, heredoc, len); /* may loop or block */
		_exit(0);
#else
		/* Delegate blocking writes to another process */
		xmove_fd(pair.wr, STDOUT_FILENO);
		re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
#endif
	}
	/* parent */
#if ENABLE_HUSH_FAST
	G.count_SIGCHLD++;
//bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
#endif
	enable_restore_tty_pgrp_on_exit();
#if !BB_MMU
	free(to_free);
#endif
	close(pair.wr);
	free(expanded);
	wait(NULL); /* wait till child has died */
}

/* squirrel != NULL means we squirrel away copies of stdin, stdout,
 * and stderr if they are redirected. */
static int setup_redirects(struct command *prog, int squirrel[])
{
	int openfd, mode;
	struct redir_struct *redir;

	for (redir = prog->redirects; redir; redir = redir->next) {
		if (redir->rd_type == REDIRECT_HEREDOC2) {
			/* rd_fd<<HERE case */
			if (squirrel && redir->rd_fd < 3
			 && squirrel[redir->rd_fd] < 0
			) {
				squirrel[redir->rd_fd] = dup(redir->rd_fd);
			}
			/* for REDIRECT_HEREDOC2, rd_filename holds _contents_
			 * of the heredoc */
			debug_printf_parse("set heredoc '%s'\n",
					redir->rd_filename);
			setup_heredoc(redir);
			continue;
		}

		if (redir->rd_dup == REDIRFD_TO_FILE) {
			/* rd_fd<*>file case (<*> is <,>,>>,<>) */
			char *p;
			if (redir->rd_filename == NULL) {
				/* Something went wrong in the parse.
				 * Pretend it didn't happen */
				bb_error_msg("bug in redirect parse");
				continue;
			}
			mode = redir_table[redir->rd_type].mode;
			p = expand_string_to_string(redir->rd_filename);
			openfd = open_or_warn(p, mode);
			free(p);
			if (openfd < 0) {
			/* this could get lost if stderr has been redirected, but
			 * bash and ash both lose it as well (though zsh doesn't!) */
//what the above comment tries to say?
				return 1;
			}
		} else {
			/* rd_fd<*>rd_dup or rd_fd<*>- cases */
			openfd = redir->rd_dup;
		}

		if (openfd != redir->rd_fd) {
			if (squirrel && redir->rd_fd < 3
			 && squirrel[redir->rd_fd] < 0
			) {
				squirrel[redir->rd_fd] = dup(redir->rd_fd);
			}
			if (openfd == REDIRFD_CLOSE) {
				/* "n>-" means "close me" */
				close(redir->rd_fd);
			} else {
				xdup2(openfd, redir->rd_fd);
				if (redir->rd_dup == REDIRFD_TO_FILE)
					close(openfd);
			}
		}
	}
	return 0;
}

static void restore_redirects(int squirrel[])
{
	int i, fd;
	for (i = 0; i < 3; i++) {
		fd = squirrel[i];
		if (fd != -1) {
			/* We simply die on error */
			xmove_fd(fd, i);
		}
	}
}


static void free_pipe_list(struct pipe *head);

/* Return code is the exit status of the pipe */
static void free_pipe(struct pipe *pi)
{
	char **p;
	struct command *command;
	struct redir_struct *r, *rnext;
	int a, i;

	if (pi->stopped_cmds > 0) /* why? */
		return;
	debug_printf_clean("run pipe: (pid %d)\n", getpid());
	for (i = 0; i < pi->num_cmds; i++) {
		command = &pi->cmds[i];
		debug_printf_clean("  command %d:\n", i);
		if (command->argv) {
			for (a = 0, p = command->argv; *p; a++, p++) {
				debug_printf_clean("   argv[%d] = %s\n", a, *p);
			}
			free_strings(command->argv);
			command->argv = NULL;
		}
		/* not "else if": on syntax error, we may have both! */
		if (command->group) {
			debug_printf_clean("   begin group (cmd_type:%d)\n",
					command->cmd_type);
			free_pipe_list(command->group);
			debug_printf_clean("   end group\n");
			command->group = NULL;
		}
		/* else is crucial here.
		 * If group != NULL, child_func is meaningless */
#if ENABLE_HUSH_FUNCTIONS
		else if (command->child_func) {
			debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
			command->child_func->parent_cmd = NULL;
		}
#endif
#if !BB_MMU
		free(command->group_as_string);
		command->group_as_string = NULL;
#endif
		for (r = command->redirects; r; r = rnext) {
			debug_printf_clean("   redirect %d%s",
					r->rd_fd, redir_table[r->rd_type].descrip);
			/* guard against the case >$FOO, where foo is unset or blank */
			if (r->rd_filename) {
				debug_printf_clean(" fname:'%s'\n", r->rd_filename);
				free(r->rd_filename);
				r->rd_filename = NULL;
			}
			debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
			rnext = r->next;
			free(r);
		}
		command->redirects = NULL;
	}
	free(pi->cmds);   /* children are an array, they get freed all at once */
	pi->cmds = NULL;
#if ENABLE_HUSH_JOB
	free(pi->cmdtext);
	pi->cmdtext = NULL;
#endif
}

static void free_pipe_list(struct pipe *head)
{
	struct pipe *pi, *next;

	for (pi = head; pi; pi = next) {
#if HAS_KEYWORDS
		debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
#endif
		free_pipe(pi);
		debug_printf_clean("pipe followup code %d\n", pi->followup);
		next = pi->next;
		/*pi->next = NULL;*/
		free(pi);
	}
}


static int run_list(struct pipe *pi);
#if BB_MMU
#define parse_stream(pstring, input, end_trigger) \
	parse_stream(input, end_trigger)
#endif
static struct pipe *parse_stream(char **pstring,
		struct in_str *input,
		int end_trigger);
static void parse_and_run_string(const char *s);


static char *find_in_path(const char *arg)
{
	char *ret = NULL;
	const char *PATH = get_local_var_value("PATH");

	if (!PATH)
		return NULL;

	while (1) {
		const char *end = strchrnul(PATH, ':');
		int sz = end - PATH; /* must be int! */

		free(ret);
		if (sz != 0) {
			ret = xasprintf("%.*s/%s", sz, PATH, arg);
		} else {
			/* We have xxx::yyyy in $PATH,
			 * it means "use current dir" */
			ret = xstrdup(arg);
		}
		if (access(ret, F_OK) == 0)
			break;

		if (*end == '\0') {
			free(ret);
			return NULL;
		}
		PATH = end + 1;
	}

	return ret;
}

static const struct built_in_command* find_builtin_helper(const char *name,
		const struct built_in_command *x,
		const struct built_in_command *end)
{
	while (x != end) {
		if (strcmp(name, x->b_cmd) != 0) {
			x++;
			continue;
		}
		debug_printf_exec("found builtin '%s'\n", name);
		return x;
	}
	return NULL;
}
static const struct built_in_command* find_builtin1(const char *name)
{
	return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
}
static const struct built_in_command* find_builtin(const char *name)
{
	const struct built_in_command *x = find_builtin1(name);
	if (x)
		return x;
	return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
}

#if ENABLE_HUSH_FUNCTIONS
static struct function **find_function_slot(const char *name)
{
	struct function **funcpp = &G.top_func;
	while (*funcpp) {
		if (strcmp(name, (*funcpp)->name) == 0) {
			break;
		}
		funcpp = &(*funcpp)->next;
	}
	return funcpp;
}

static const struct function *find_function(const char *name)
{
	const struct function *funcp = *find_function_slot(name);
	if (funcp)
		debug_printf_exec("found function '%s'\n", name);
	return funcp;
}

/* Note: takes ownership on name ptr */
static struct function *new_function(char *name)
{
	struct function **funcpp = find_function_slot(name);
	struct function *funcp = *funcpp;

	if (funcp != NULL) {
		struct command *cmd = funcp->parent_cmd;
		debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
		if (!cmd) {
			debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
			free(funcp->name);
			/* Note: if !funcp->body, do not free body_as_string!
			 * This is a special case of "-F name body" function:
			 * body_as_string was not malloced! */
			if (funcp->body) {
				free_pipe_list(funcp->body);
# if !BB_MMU
				free(funcp->body_as_string);
# endif
			}
		} else {
			debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
			cmd->argv[0] = funcp->name;
			cmd->group = funcp->body;
# if !BB_MMU
			cmd->group_as_string = funcp->body_as_string;
# endif
		}
	} else {
		debug_printf_exec("remembering new function '%s'\n", name);
		funcp = *funcpp = xzalloc(sizeof(*funcp));
		/*funcp->next = NULL;*/
	}

	funcp->name = name;
	return funcp;
}

static void unset_func(const char *name)
{
	struct function **funcpp = find_function_slot(name);
	struct function *funcp = *funcpp;

	if (funcp != NULL) {
		debug_printf_exec("freeing function '%s'\n", funcp->name);
		*funcpp = funcp->next;
		/* funcp is unlinked now, deleting it.
		 * Note: if !funcp->body, the function was created by
		 * "-F name body", do not free ->body_as_string
		 * and ->name as they were not malloced. */
		if (funcp->body) {
			free_pipe_list(funcp->body);
			free(funcp->name);
# if !BB_MMU
			free(funcp->body_as_string);
# endif
		}
		free(funcp);
	}
}

# if BB_MMU
#define exec_function(to_free, funcp, argv) \
	exec_function(funcp, argv)
# endif
static void exec_function(char ***to_free,
		const struct function *funcp,
		char **argv) NORETURN;
static void exec_function(char ***to_free,
		const struct function *funcp,
		char **argv)
{
# if BB_MMU
	int n = 1;

	argv[0] = G.global_argv[0];
	G.global_argv = argv;
	while (*++argv)
		n++;
	G.global_argc = n;
	/* On MMU, funcp->body is always non-NULL */
	n = run_list(funcp->body);
	fflush_all();
	_exit(n);
# else
	re_execute_shell(to_free,
			funcp->body_as_string,
			G.global_argv[0],
			argv + 1,
			NULL);
# endif
}

static int run_function(const struct function *funcp, char **argv)
{
	int rc;
	save_arg_t sv;
	smallint sv_flg;

	save_and_replace_G_args(&sv, argv);

	/* "we are in function, ok to use return" */
	sv_flg = G.flag_return_in_progress;
	G.flag_return_in_progress = -1;
# if ENABLE_HUSH_LOCAL
	G.func_nest_level++;
# endif

	/* On MMU, funcp->body is always non-NULL */
# if !BB_MMU
	if (!funcp->body) {
		/* Function defined by -F */
		parse_and_run_string(funcp->body_as_string);
		rc = G.last_exitcode;
	} else
# endif
	{
		rc = run_list(funcp->body);
	}

# if ENABLE_HUSH_LOCAL
	{
		struct variable *var;
		struct variable **var_pp;

		var_pp = &G.top_var;
		while ((var = *var_pp) != NULL) {
			if (var->func_nest_level < G.func_nest_level) {
				var_pp = &var->next;
				continue;
			}
			/* Unexport */
			if (var->flg_export)
				bb_unsetenv(var->varstr);
			/* Remove from global list */
			*var_pp = var->next;
			/* Free */
			if (!var->max_len)
				free(var->varstr);
			free(var);
		}
		G.func_nest_level--;
	}
# endif
	G.flag_return_in_progress = sv_flg;

	restore_G_args(&sv, argv);

	return rc;
}
#endif /* ENABLE_HUSH_FUNCTIONS */


#if BB_MMU
#define exec_builtin(to_free, x, argv) \
	exec_builtin(x, argv)
#else
#define exec_builtin(to_free, x, argv) \
	exec_builtin(to_free, argv)
#endif
static void exec_builtin(char ***to_free,
		const struct built_in_command *x,
		char **argv) NORETURN;
static void exec_builtin(char ***to_free,
		const struct built_in_command *x,
		char **argv)
{
#if BB_MMU
	int rcode = x->b_function(argv);
	fflush_all();
	_exit(rcode);
#else
	/* On NOMMU, we must never block!
	 * Example: { sleep 99 | read line; } & echo Ok
	 */
	re_execute_shell(to_free,
			argv[0],
			G.global_argv[0],
			G.global_argv + 1,
			argv);
#endif
}


static void execvp_or_die(char **argv) NORETURN;
static void execvp_or_die(char **argv)
{
	debug_printf_exec("execing '%s'\n", argv[0]);
	sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
	execvp(argv[0], argv);
	bb_perror_msg("can't execute '%s'", argv[0]);
	_exit(127); /* bash compat */
}

#if BB_MMU
#define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
	pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
#define pseudo_exec(nommu_save, command, argv_expanded) \
	pseudo_exec(command, argv_expanded)
#endif

/* Called after [v]fork() in run_pipe, or from builtin_exec.
 * Never returns.
 * Don't exit() here.  If you don't exec, use _exit instead.
 * The at_exit handlers apparently confuse the calling process,
 * in particular stdin handling.  Not sure why? -- because of vfork! (vda) */
static void pseudo_exec_argv(nommu_save_t *nommu_save,
		char **argv, int assignment_cnt,
		char **argv_expanded) NORETURN;
static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
		char **argv, int assignment_cnt,
		char **argv_expanded)
{
	char **new_env;

	/* Case when we are here: ... | var=val | ... */
	if (!argv[assignment_cnt])
		_exit(EXIT_SUCCESS);

	new_env = expand_assignments(argv, assignment_cnt);
#if BB_MMU
	set_vars_and_save_old(new_env);
	free(new_env); /* optional */
	/* we can also destroy set_vars_and_save_old's return value,
	 * to save memory */
#else
	nommu_save->new_env = new_env;
	nommu_save->old_vars = set_vars_and_save_old(new_env);
#endif
	if (argv_expanded) {
		argv = argv_expanded;
	} else {
		argv = expand_strvec_to_strvec(argv + assignment_cnt);
#if !BB_MMU
		nommu_save->argv = argv;
#endif
	}

#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
	if (strchr(argv[0], '/') != NULL)
		goto skip;
#endif

	/* Check if the command matches any of the builtins.
	 * Depending on context, this might be redundant.  But it's
	 * easier to waste a few CPU cycles than it is to figure out
	 * if this is one of those cases.
	 */
	{
		/* On NOMMU, it is more expensive to re-execute shell
		 * just in order to run echo or test builtin.
		 * It's better to skip it here and run corresponding
		 * non-builtin later. */
		const struct built_in_command *x;
		x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
		if (x) {
			exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
		}
	}
#if ENABLE_HUSH_FUNCTIONS
	/* Check if the command matches any functions */
	{
		const struct function *funcp = find_function(argv[0]);
		if (funcp) {
			exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
		}
	}
#endif

#if ENABLE_FEATURE_SH_STANDALONE
	/* Check if the command matches any busybox applets */
	{
		int a = find_applet_by_name(argv[0]);
		if (a >= 0) {
# if BB_MMU /* see above why on NOMMU it is not allowed */
			if (APPLET_IS_NOEXEC(a)) {
				debug_printf_exec("running applet '%s'\n", argv[0]);
				run_applet_no_and_exit(a, argv);
			}
# endif
			/* Re-exec ourselves */
			debug_printf_exec("re-execing applet '%s'\n", argv[0]);
			sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
			execv(bb_busybox_exec_path, argv);
			/* If they called chroot or otherwise made the binary no longer
			 * executable, fall through */
		}
	}
#endif

#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
 skip:
#endif
	execvp_or_die(argv);
}

/* Called after [v]fork() in run_pipe
 */
static void pseudo_exec(nommu_save_t *nommu_save,
		struct command *command,
		char **argv_expanded) NORETURN;
static void pseudo_exec(nommu_save_t *nommu_save,
		struct command *command,
		char **argv_expanded)
{
	if (command->argv) {
		pseudo_exec_argv(nommu_save, command->argv,
				command->assignment_cnt, argv_expanded);
	}

	if (command->group) {
		/* Cases when we are here:
		 * ( list )
		 * { list } &
		 * ... | ( list ) | ...
		 * ... | { list } | ...
		 */
#if BB_MMU
		int rcode;
		debug_printf_exec("pseudo_exec: run_list\n");
		reset_traps_to_defaults();
		rcode = run_list(command->group);
		/* OK to leak memory by not calling free_pipe_list,
		 * since this process is about to exit */
		_exit(rcode);
#else
		re_execute_shell(&nommu_save->argv_from_re_execing,
				command->group_as_string,
				G.global_argv[0],
				G.global_argv + 1,
				NULL);
#endif
	}

	/* Case when we are here: ... | >file */
	debug_printf_exec("pseudo_exec'ed null command\n");
	_exit(EXIT_SUCCESS);
}

#if ENABLE_HUSH_JOB
static const char *get_cmdtext(struct pipe *pi)
{
	char **argv;
	char *p;
	int len;

	/* This is subtle. ->cmdtext is created only on first backgrounding.
	 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
	 * On subsequent bg argv is trashed, but we won't use it */
	if (pi->cmdtext)
		return pi->cmdtext;
	argv = pi->cmds[0].argv;
	if (!argv || !argv[0]) {
		pi->cmdtext = xzalloc(1);
		return pi->cmdtext;
	}

	len = 0;
	do {
		len += strlen(*argv) + 1;
	} while (*++argv);
	p = xmalloc(len);
	pi->cmdtext = p;
	argv = pi->cmds[0].argv;
	do {
		len = strlen(*argv);
		memcpy(p, *argv, len);
		p += len;
		*p++ = ' ';
	} while (*++argv);
	p[-1] = '\0';
	return pi->cmdtext;
}

static void insert_bg_job(struct pipe *pi)
{
	struct pipe *job, **jobp;
	int i;

	/* Linear search for the ID of the job to use */
	pi->jobid = 1;
	for (job = G.job_list; job; job = job->next)
		if (job->jobid >= pi->jobid)
			pi->jobid = job->jobid + 1;

	/* Add job to the list of running jobs */
	jobp = &G.job_list;
	while ((job = *jobp) != NULL)
		jobp = &job->next;
	job = *jobp = xmalloc(sizeof(*job));

	*job = *pi; /* physical copy */
	job->next = NULL;
	job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
	/* Cannot copy entire pi->cmds[] vector! This causes double frees */
	for (i = 0; i < pi->num_cmds; i++) {
		job->cmds[i].pid = pi->cmds[i].pid;
		/* all other fields are not used and stay zero */
	}
	job->cmdtext = xstrdup(get_cmdtext(pi));

	if (G_interactive_fd)
		printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
	/* Last command's pid goes to $! */
	G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
	G.last_jobid = job->jobid;
}

static void remove_bg_job(struct pipe *pi)
{
	struct pipe *prev_pipe;

	if (pi == G.job_list) {
		G.job_list = pi->next;
	} else {
		prev_pipe = G.job_list;
		while (prev_pipe->next != pi)
			prev_pipe = prev_pipe->next;
		prev_pipe->next = pi->next;
	}
	if (G.job_list)
		G.last_jobid = G.job_list->jobid;
	else
		G.last_jobid = 0;
}

/* Remove a backgrounded job */
static void delete_finished_bg_job(struct pipe *pi)
{
	remove_bg_job(pi);
	pi->stopped_cmds = 0;
	free_pipe(pi);
	free(pi);
}
#endif /* JOB */

/* Check to see if any processes have exited -- if they
 * have, figure out why and see if a job has completed */
static int checkjobs(struct pipe* fg_pipe)
{
	int attributes;
	int status;
#if ENABLE_HUSH_JOB
	struct pipe *pi;
#endif
	pid_t childpid;
	int rcode = 0;

	debug_printf_jobs("checkjobs %p\n", fg_pipe);

	attributes = WUNTRACED;
	if (fg_pipe == NULL)
		attributes |= WNOHANG;

	errno = 0;
#if ENABLE_HUSH_FAST
	if (G.handled_SIGCHLD == G.count_SIGCHLD) {
//bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
//getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
		/* There was neither fork nor SIGCHLD since last waitpid */
		/* Avoid doing waitpid syscall if possible */
		if (!G.we_have_children) {
			errno = ECHILD;
			return -1;
		}
		if (fg_pipe == NULL) { /* is WNOHANG set? */
			/* We have children, but they did not exit
			 * or stop yet (we saw no SIGCHLD) */
			return 0;
		}
		/* else: !WNOHANG, waitpid will block, can't short-circuit */
	}
#endif

/* Do we do this right?
 * bash-3.00# sleep 20 | false
 * <ctrl-Z pressed>
 * [3]+  Stopped          sleep 20 | false
 * bash-3.00# echo $?
 * 1   <========== bg pipe is not fully done, but exitcode is already known!
 * [hush 1.14.0: yes we do it right]
 */
 wait_more:
	while (1) {
		int i;
		int dead;

#if ENABLE_HUSH_FAST
		i = G.count_SIGCHLD;
#endif
		childpid = waitpid(-1, &status, attributes);
		if (childpid <= 0) {
			if (childpid && errno != ECHILD)
				bb_perror_msg("waitpid");
#if ENABLE_HUSH_FAST
			else { /* Until next SIGCHLD, waitpid's are useless */
				G.we_have_children = (childpid == 0);
				G.handled_SIGCHLD = i;
//bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
			}
#endif
			break;
		}
		dead = WIFEXITED(status) || WIFSIGNALED(status);

#if DEBUG_JOBS
		if (WIFSTOPPED(status))
			debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
					childpid, WSTOPSIG(status), WEXITSTATUS(status));
		if (WIFSIGNALED(status))
			debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
					childpid, WTERMSIG(status), WEXITSTATUS(status));
		if (WIFEXITED(status))
			debug_printf_jobs("pid %d exited, exitcode %d\n",
					childpid, WEXITSTATUS(status));
#endif
		/* Were we asked to wait for fg pipe? */
		if (fg_pipe) {
			for (i = 0; i < fg_pipe->num_cmds; i++) {
				debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
				if (fg_pipe->cmds[i].pid != childpid)
					continue;
				if (dead) {
					fg_pipe->cmds[i].pid = 0;
					fg_pipe->alive_cmds--;
					if (i == fg_pipe->num_cmds - 1) {
						/* last process gives overall exitstatus */
						rcode = WEXITSTATUS(status);
						/* bash prints killer signal's name for *last*
						 * process in pipe (prints just newline for SIGINT).
						 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
						 */
						if (WIFSIGNALED(status)) {
							int sig = WTERMSIG(status);
							printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
							/* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
							 * Maybe we need to use sig | 128? */
							rcode = sig + 128;
						}
						IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
					}
				} else {
					fg_pipe->cmds[i].is_stopped = 1;
					fg_pipe->stopped_cmds++;
				}
				debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
						fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
				if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
					/* All processes in fg pipe have exited or stopped */
/* Note: *non-interactive* bash does not continue if all processes in fg pipe
 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
 * and "killall -STOP cat" */
					if (G_interactive_fd) {
#if ENABLE_HUSH_JOB
						if (fg_pipe->alive_cmds)
							insert_bg_job(fg_pipe);
#endif
						return rcode;
					}
					if (!fg_pipe->alive_cmds)
						return rcode;
				}
				/* There are still running processes in the fg pipe */
				goto wait_more; /* do waitpid again */
			}
			/* it wasnt fg_pipe, look for process in bg pipes */
		}

#if ENABLE_HUSH_JOB
		/* We asked to wait for bg or orphaned children */
		/* No need to remember exitcode in this case */
		for (pi = G.job_list; pi; pi = pi->next) {
			for (i = 0; i < pi->num_cmds; i++) {
				if (pi->cmds[i].pid == childpid)
					goto found_pi_and_prognum;
			}
		}
		/* Happens when shell is used as init process (init=/bin/sh) */
		debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
		continue; /* do waitpid again */

 found_pi_and_prognum:
		if (dead) {
			/* child exited */
			pi->cmds[i].pid = 0;
			pi->alive_cmds--;
			if (!pi->alive_cmds) {
				if (G_interactive_fd)
					printf(JOB_STATUS_FORMAT, pi->jobid,
							"Done", pi->cmdtext);
				delete_finished_bg_job(pi);
			}
		} else {
			/* child stopped */
			pi->cmds[i].is_stopped = 1;
			pi->stopped_cmds++;
		}
#endif
	} /* while (waitpid succeeds)... */

	return rcode;
}

#if ENABLE_HUSH_JOB
static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
{
	pid_t p;
	int rcode = checkjobs(fg_pipe);
	if (G_saved_tty_pgrp) {
		/* Job finished, move the shell to the foreground */
		p = getpgrp(); /* our process group id */
		debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
		tcsetpgrp(G_interactive_fd, p);
	}
	return rcode;
}
#endif

/* Start all the jobs, but don't wait for anything to finish.
 * See checkjobs().
 *
 * Return code is normally -1, when the caller has to wait for children
 * to finish to determine the exit status of the pipe.  If the pipe
 * is a simple builtin command, however, the action is done by the
 * time run_pipe returns, and the exit code is provided as the
 * return value.
 *
 * Returns -1 only if started some children. IOW: we have to
 * mask out retvals of builtins etc with 0xff!
 *
 * The only case when we do not need to [v]fork is when the pipe
 * is single, non-backgrounded, non-subshell command. Examples:
 * cmd ; ...   { list } ; ...
 * cmd && ...  { list } && ...
 * cmd || ...  { list } || ...
 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
 * or (if SH_STANDALONE) an applet, and we can run the { list }
 * with run_list. If it isn't one of these, we fork and exec cmd.
 *
 * Cases when we must fork:
 * non-single:   cmd | cmd
 * backgrounded: cmd &     { list } &
 * subshell:     ( list ) [&]
 */
static NOINLINE int run_pipe(struct pipe *pi)
{
	static const char *const null_ptr = NULL;
	int i;
	int nextin;
	struct command *command;
	char **argv_expanded;
	char **argv;
	char *p;
	/* it is not always needed, but we aim to smaller code */
	int squirrel[] = { -1, -1, -1 };
	int rcode;

	debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
	debug_enter();

	IF_HUSH_JOB(pi->pgrp = -1;)
	pi->stopped_cmds = 0;
	command = &(pi->cmds[0]);
	argv_expanded = NULL;

	if (pi->num_cmds != 1
	 || pi->followup == PIPE_BG
	 || command->cmd_type == CMD_SUBSHELL
	) {
		goto must_fork;
	}

	pi->alive_cmds = 1;

	debug_printf_exec(": group:%p argv:'%s'\n",
		command->group, command->argv ? command->argv[0] : "NONE");

	if (command->group) {
#if ENABLE_HUSH_FUNCTIONS
		if (command->cmd_type == CMD_FUNCDEF) {
			/* "executing" func () { list } */
			struct function *funcp;

			funcp = new_function(command->argv[0]);
			/* funcp->name is already set to argv[0] */
			funcp->body = command->group;
# if !BB_MMU
			funcp->body_as_string = command->group_as_string;
			command->group_as_string = NULL;
# endif
			command->group = NULL;
			command->argv[0] = NULL;
			debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
			funcp->parent_cmd = command;
			command->child_func = funcp;

			debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
			debug_leave();
			return EXIT_SUCCESS;
		}
#endif
		/* { list } */
		debug_printf("non-subshell group\n");
		rcode = 1; /* exitcode if redir failed */
		if (setup_redirects(command, squirrel) == 0) {
			debug_printf_exec(": run_list\n");
			rcode = run_list(command->group) & 0xff;
		}
		restore_redirects(squirrel);
		IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
		debug_leave();
		debug_printf_exec("run_pipe: return %d\n", rcode);
		return rcode;
	}

	argv = command->argv ? command->argv : (char **) &null_ptr;
	{
		const struct built_in_command *x;
#if ENABLE_HUSH_FUNCTIONS
		const struct function *funcp;
#else
		enum { funcp = 0 };
#endif
		char **new_env = NULL;
		struct variable *old_vars = NULL;

		if (argv[command->assignment_cnt] == NULL) {
			/* Assignments, but no command */
			/* Ensure redirects take effect (that is, create files).
			 * Try "a=t >file": */
			rcode = setup_redirects(command, squirrel);
			restore_redirects(squirrel);
			/* Set shell variables */
			while (*argv) {
				p = expand_string_to_string(*argv);
				debug_printf_exec("set shell var:'%s'->'%s'\n",
						*argv, p);
				set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
				argv++;
			}
			/* Redirect error sets $? to 1. Othervise,
			 * if evaluating assignment value set $?, retain it.
			 * Try "false; q=`exit 2`; echo $?" - should print 2: */
			if (rcode == 0)
				rcode = G.last_exitcode;
			/* Do we need to flag set_local_var() errors?
			 * "assignment to readonly var" and "putenv error"
			 */
			IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
			debug_leave();
			debug_printf_exec("run_pipe: return %d\n", rcode);
			return rcode;
		}

		/* Expand the rest into (possibly) many strings each */
		if (0) {}
#if ENABLE_HUSH_BASH_COMPAT
		else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
			argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
		}
#endif
#ifdef CMD_SINGLEWORD_NOGLOB_COND
		else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
			argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);

		}
#endif
		else {
			argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
		}

		/* if someone gives us an empty string: `cmd with empty output` */
		if (!argv_expanded[0]) {
			free(argv_expanded);
			debug_leave();
			return G.last_exitcode;
		}

		x = find_builtin(argv_expanded[0]);
#if ENABLE_HUSH_FUNCTIONS
		funcp = NULL;
		if (!x)
			funcp = find_function(argv_expanded[0]);
#endif
		if (x || funcp) {
			if (!funcp) {
				if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
					debug_printf("exec with redirects only\n");
					rcode = setup_redirects(command, NULL);
					goto clean_up_and_ret1;
				}
			}
			/* setup_redirects acts on file descriptors, not FILEs.
			 * This is perfect for work that comes after exec().
			 * Is it really safe for inline use?  Experimentally,
			 * things seem to work. */
			rcode = setup_redirects(command, squirrel);
			if (rcode == 0) {
				new_env = expand_assignments(argv, command->assignment_cnt);
				old_vars = set_vars_and_save_old(new_env);
				if (!funcp) {
					debug_printf_exec(": builtin '%s' '%s'...\n",
						x->b_cmd, argv_expanded[1]);
					rcode = x->b_function(argv_expanded) & 0xff;
					fflush_all();
				}
#if ENABLE_HUSH_FUNCTIONS
				else {
# if ENABLE_HUSH_LOCAL
					struct variable **sv;
					sv = G.shadowed_vars_pp;
					G.shadowed_vars_pp = &old_vars;
# endif
					debug_printf_exec(": function '%s' '%s'...\n",
						funcp->name, argv_expanded[1]);
					rcode = run_function(funcp, argv_expanded) & 0xff;
# if ENABLE_HUSH_LOCAL
					G.shadowed_vars_pp = sv;
# endif
				}
#endif
			}
#if ENABLE_FEATURE_SH_STANDALONE
 clean_up_and_ret:
#endif
			restore_redirects(squirrel);
			unset_vars(new_env);
			add_vars(old_vars);
 clean_up_and_ret1:
			free(argv_expanded);
			IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
			debug_leave();
			debug_printf_exec("run_pipe return %d\n", rcode);
			return rcode;
		}

#if ENABLE_FEATURE_SH_STANDALONE
		i = find_applet_by_name(argv_expanded[0]);
		if (i >= 0 && APPLET_IS_NOFORK(i)) {
			rcode = setup_redirects(command, squirrel);
			if (rcode == 0) {
				new_env = expand_assignments(argv, command->assignment_cnt);
				old_vars = set_vars_and_save_old(new_env);
				debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
					argv_expanded[0], argv_expanded[1]);
				rcode = run_nofork_applet(i, argv_expanded);
			}
			goto clean_up_and_ret;
		}
#endif
		/* It is neither builtin nor applet. We must fork. */
	}

 must_fork:
	/* NB: argv_expanded may already be created, and that
	 * might include `cmd` runs! Do not rerun it! We *must*
	 * use argv_expanded if it's non-NULL */

	/* Going to fork a child per each pipe member */
	pi->alive_cmds = 0;
	nextin = 0;

	for (i = 0; i < pi->num_cmds; i++) {
		struct fd_pair pipefds;
#if !BB_MMU
		volatile nommu_save_t nommu_save;
		nommu_save.new_env = NULL;
		nommu_save.old_vars = NULL;
		nommu_save.argv = NULL;
		nommu_save.argv_from_re_execing = NULL;
#endif
		command = &(pi->cmds[i]);
		if (command->argv) {
			debug_printf_exec(": pipe member '%s' '%s'...\n",
					command->argv[0], command->argv[1]);
		} else {
			debug_printf_exec(": pipe member with no argv\n");
		}

		/* pipes are inserted between pairs of commands */
		pipefds.rd = 0;
		pipefds.wr = 1;
		if ((i + 1) < pi->num_cmds)
			xpiped_pair(pipefds);

		command->pid = BB_MMU ? fork() : vfork();
		if (!command->pid) { /* child */
#if ENABLE_HUSH_JOB
			disable_restore_tty_pgrp_on_exit();
			CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */

			/* Every child adds itself to new process group
			 * with pgid == pid_of_first_child_in_pipe */
			if (G.run_list_level == 1 && G_interactive_fd) {
				pid_t pgrp;
				pgrp = pi->pgrp;
				if (pgrp < 0) /* true for 1st process only */
					pgrp = getpid();
				if (setpgid(0, pgrp) == 0
				 && pi->followup != PIPE_BG
				 && G_saved_tty_pgrp /* we have ctty */
				) {
					/* We do it in *every* child, not just first,
					 * to avoid races */
					tcsetpgrp(G_interactive_fd, pgrp);
				}
			}
#endif
			if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
				/* 1st cmd in backgrounded pipe
				 * should have its stdin /dev/null'ed */
				close(0);
				if (open(bb_dev_null, O_RDONLY))
					xopen("/", O_RDONLY);
			} else {
				xmove_fd(nextin, 0);
			}
			xmove_fd(pipefds.wr, 1);
			if (pipefds.rd > 1)
				close(pipefds.rd);
			/* Like bash, explicit redirects override pipes,
			 * and the pipe fd is available for dup'ing. */
			if (setup_redirects(command, NULL))
				_exit(1);

			/* Restore default handlers just prior to exec */
			/*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */

			/* Stores to nommu_save list of env vars putenv'ed
			 * (NOMMU, on MMU we don't need that) */
			/* cast away volatility... */
			pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
			/* pseudo_exec() does not return */
		}

		/* parent or error */
#if ENABLE_HUSH_FAST
		G.count_SIGCHLD++;
//bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
#endif
		enable_restore_tty_pgrp_on_exit();
#if !BB_MMU
		/* Clean up after vforked child */
		free(nommu_save.argv);
		free(nommu_save.argv_from_re_execing);
		unset_vars(nommu_save.new_env);
		add_vars(nommu_save.old_vars);
#endif
		free(argv_expanded);
		argv_expanded = NULL;
		if (command->pid < 0) { /* [v]fork failed */
			/* Clearly indicate, was it fork or vfork */
			bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
		} else {
			pi->alive_cmds++;
#if ENABLE_HUSH_JOB
			/* Second and next children need to know pid of first one */
			if (pi->pgrp < 0)
				pi->pgrp = command->pid;
#endif
		}

		if (i)
			close(nextin);
		if ((i + 1) < pi->num_cmds)
			close(pipefds.wr);
		/* Pass read (output) pipe end to next iteration */
		nextin = pipefds.rd;
	}

	if (!pi->alive_cmds) {
		debug_leave();
		debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
		return 1;
	}

	debug_leave();
	debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
	return -1;
}

#ifndef debug_print_tree
static void debug_print_tree(struct pipe *pi, int lvl)
{
	static const char *const PIPE[] = {
		[PIPE_SEQ] = "SEQ",
		[PIPE_AND] = "AND",
		[PIPE_OR ] = "OR" ,
		[PIPE_BG ] = "BG" ,
	};
	static const char *RES[] = {
		[RES_NONE ] = "NONE" ,
# if ENABLE_HUSH_IF
		[RES_IF   ] = "IF"   ,
		[RES_THEN ] = "THEN" ,
		[RES_ELIF ] = "ELIF" ,
		[RES_ELSE ] = "ELSE" ,
		[RES_FI   ] = "FI"   ,
# endif
# if ENABLE_HUSH_LOOPS
		[RES_FOR  ] = "FOR"  ,
		[RES_WHILE] = "WHILE",
		[RES_UNTIL] = "UNTIL",
		[RES_DO   ] = "DO"   ,
		[RES_DONE ] = "DONE" ,
# endif
# if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
		[RES_IN   ] = "IN"   ,
# endif
# if ENABLE_HUSH_CASE
		[RES_CASE ] = "CASE" ,
		[RES_CASE_IN ] = "CASE_IN" ,
		[RES_MATCH] = "MATCH",
		[RES_CASE_BODY] = "CASE_BODY",
		[RES_ESAC ] = "ESAC" ,
# endif
		[RES_XXXX ] = "XXXX" ,
		[RES_SNTX ] = "SNTX" ,
	};
	static const char *const CMDTYPE[] = {
		"{}",
		"()",
		"[noglob]",
# if ENABLE_HUSH_FUNCTIONS
		"func()",
# endif
	};

	int pin, prn;

	pin = 0;
	while (pi) {
		fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
				pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
		prn = 0;
		while (prn < pi->num_cmds) {
			struct command *command = &pi->cmds[prn];
			char **argv = command->argv;

			fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
					lvl*2, "", prn,
					command->assignment_cnt);
			if (command->group) {
				fprintf(stderr, " group %s: (argv=%p)%s%s\n",
						CMDTYPE[command->cmd_type],
						argv
# if !BB_MMU
						, " group_as_string:", command->group_as_string
# else
						, "", ""
# endif
				);
				debug_print_tree(command->group, lvl+1);
				prn++;
				continue;
			}
			if (argv) while (*argv) {
				fprintf(stderr, " '%s'", *argv);
				argv++;
			}
			fprintf(stderr, "\n");
			prn++;
		}
		pi = pi->next;
		pin++;
	}
}
#endif /* debug_print_tree */

/* NB: called by pseudo_exec, and therefore must not modify any
 * global data until exec/_exit (we can be a child after vfork!) */
static int run_list(struct pipe *pi)
{
#if ENABLE_HUSH_CASE
	char *case_word = NULL;
#endif
#if ENABLE_HUSH_LOOPS
	struct pipe *loop_top = NULL;
	char **for_lcur = NULL;
	char **for_list = NULL;
#endif
	smallint last_followup;
	smalluint rcode;
#if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
	smalluint cond_code = 0;
#else
	enum { cond_code = 0 };
#endif
#if HAS_KEYWORDS
	smallint rword; /* enum reserved_style */
	smallint last_rword; /* ditto */
#endif

	debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
	debug_enter();

#if ENABLE_HUSH_LOOPS
	/* Check syntax for "for" */
	for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
		if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
			continue;
		/* current word is FOR or IN (BOLD in comments below) */
		if (cpipe->next == NULL) {
			syntax_error("malformed for");
			debug_leave();
			debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
			return 1;
		}
		/* "FOR v; do ..." and "for v IN a b; do..." are ok */
		if (cpipe->next->res_word == RES_DO)
			continue;
		/* next word is not "do". It must be "in" then ("FOR v in ...") */
		if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
		 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
		) {
			syntax_error("malformed for");
			debug_leave();
			debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
			return 1;
		}
	}
#endif

	/* Past this point, all code paths should jump to ret: label
	 * in order to return, no direct "return" statements please.
	 * This helps to ensure that no memory is leaked. */

#if ENABLE_HUSH_JOB
	G.run_list_level++;
#endif

#if HAS_KEYWORDS
	rword = RES_NONE;
	last_rword = RES_XXXX;
#endif
	last_followup = PIPE_SEQ;
	rcode = G.last_exitcode;

	/* Go through list of pipes, (maybe) executing them. */
	for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
		if (G.flag_SIGINT)
			break;

		IF_HAS_KEYWORDS(rword = pi->res_word;)
		debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
				rword, cond_code, last_rword);
#if ENABLE_HUSH_LOOPS
		if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
		 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
		) {
			/* start of a loop: remember where loop starts */
			loop_top = pi;
			G.depth_of_loop++;
		}
#endif
		/* Still in the same "if...", "then..." or "do..." branch? */
		if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
			if ((rcode == 0 && last_followup == PIPE_OR)
			 || (rcode != 0 && last_followup == PIPE_AND)
			) {
				/* It is "<true> || CMD" or "<false> && CMD"
				 * and we should not execute CMD */
				debug_printf_exec("skipped cmd because of || or &&\n");
				last_followup = pi->followup;
				continue;
			}
		}
		last_followup = pi->followup;
		IF_HAS_KEYWORDS(last_rword = rword;)
#if ENABLE_HUSH_IF
		if (cond_code) {
			if (rword == RES_THEN) {
				/* if false; then ... fi has exitcode 0! */
				G.last_exitcode = rcode = EXIT_SUCCESS;
				/* "if <false> THEN cmd": skip cmd */
				continue;
			}
		} else {
			if (rword == RES_ELSE || rword == RES_ELIF) {
				/* "if <true> then ... ELSE/ELIF cmd":
				 * skip cmd and all following ones */
				break;
			}
		}
#endif
#if ENABLE_HUSH_LOOPS
		if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
			if (!for_lcur) {
				/* first loop through for */

				static const char encoded_dollar_at[] ALIGN1 = {
					SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
				}; /* encoded representation of "$@" */
				static const char *const encoded_dollar_at_argv[] = {
					encoded_dollar_at, NULL
				}; /* argv list with one element: "$@" */
				char **vals;

				vals = (char**)encoded_dollar_at_argv;
				if (pi->next->res_word == RES_IN) {
					/* if no variable values after "in" we skip "for" */
					if (!pi->next->cmds[0].argv) {
						G.last_exitcode = rcode = EXIT_SUCCESS;
						debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
						break;
					}
					vals = pi->next->cmds[0].argv;
				} /* else: "for var; do..." -> assume "$@" list */
				/* create list of variable values */
				debug_print_strings("for_list made from", vals);
				for_list = expand_strvec_to_strvec(vals);
				for_lcur = for_list;
				debug_print_strings("for_list", for_list);
			}
			if (!*for_lcur) {
				/* "for" loop is over, clean up */
				free(for_list);
				for_list = NULL;
				for_lcur = NULL;
				break;
			}
			/* Insert next value from for_lcur */
			/* note: *for_lcur already has quotes removed, $var expanded, etc */
			set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
			continue;
		}
		if (rword == RES_IN) {
			continue; /* "for v IN list;..." - "in" has no cmds anyway */
		}
		if (rword == RES_DONE) {
			continue; /* "done" has no cmds too */
		}
#endif
#if ENABLE_HUSH_CASE
		if (rword == RES_CASE) {
			case_word = expand_strvec_to_string(pi->cmds->argv);
			continue;
		}
		if (rword == RES_MATCH) {
			char **argv;

			if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
				break;
			/* all prev words didn't match, does this one match? */
			argv = pi->cmds->argv;
			while (*argv) {
				char *pattern = expand_string_to_string(*argv);
				/* TODO: which FNM_xxx flags to use? */
				cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
				free(pattern);
				if (cond_code == 0) { /* match! we will execute this branch */
					free(case_word); /* make future "word)" stop */
					case_word = NULL;
					break;
				}
				argv++;
			}
			continue;
		}
		if (rword == RES_CASE_BODY) { /* inside of a case branch */
			if (cond_code != 0)
				continue; /* not matched yet, skip this pipe */
		}
#endif
		/* Just pressing <enter> in shell should check for jobs.
		 * OTOH, in non-interactive shell this is useless
		 * and only leads to extra job checks */
		if (pi->num_cmds == 0) {
			if (G_interactive_fd)
				goto check_jobs_and_continue;
			continue;
		}

		/* After analyzing all keywords and conditions, we decided
		 * to execute this pipe. NB: have to do checkjobs(NULL)
		 * after run_pipe to collect any background children,
		 * even if list execution is to be stopped. */
		debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
		{
			int r;
#if ENABLE_HUSH_LOOPS
			G.flag_break_continue = 0;
#endif
			rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
			if (r != -1) {
				/* We ran a builtin, function, or group.
				 * rcode is already known
				 * and we don't need to wait for anything. */
				G.last_exitcode = rcode;
				debug_printf_exec(": builtin/func exitcode %d\n", rcode);
				check_and_run_traps(0);
#if ENABLE_HUSH_LOOPS
				/* Was it "break" or "continue"? */
				if (G.flag_break_continue) {
					smallint fbc = G.flag_break_continue;
					/* We might fall into outer *loop*,
					 * don't want to break it too */
					if (loop_top) {
						G.depth_break_continue--;
						if (G.depth_break_continue == 0)
							G.flag_break_continue = 0;
						/* else: e.g. "continue 2" should *break* once, *then* continue */
					} /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
					if (G.depth_break_continue != 0 || fbc == BC_BREAK)
						goto check_jobs_and_break;
					/* "continue": simulate end of loop */
					rword = RES_DONE;
					continue;
				}
#endif
#if ENABLE_HUSH_FUNCTIONS
				if (G.flag_return_in_progress == 1) {
					/* same as "goto check_jobs_and_break" */
					checkjobs(NULL);
					break;
				}
#endif
			} else if (pi->followup == PIPE_BG) {
				/* What does bash do with attempts to background builtins? */
				/* even bash 3.2 doesn't do that well with nested bg:
				 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
				 * I'm NOT treating inner &'s as jobs */
				check_and_run_traps(0);
#if ENABLE_HUSH_JOB
				if (G.run_list_level == 1)
					insert_bg_job(pi);
#endif
				G.last_exitcode = rcode = EXIT_SUCCESS;
				debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
			} else {
#if ENABLE_HUSH_JOB
				if (G.run_list_level == 1 && G_interactive_fd) {
					/* Waits for completion, then fg's main shell */
					rcode = checkjobs_and_fg_shell(pi);
					debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
					check_and_run_traps(0);
				} else
#endif
				{ /* This one just waits for completion */
					rcode = checkjobs(pi);
					debug_printf_exec(": checkjobs exitcode %d\n", rcode);
					check_and_run_traps(0);
				}
				G.last_exitcode = rcode;
			}
		}

		/* Analyze how result affects subsequent commands */
#if ENABLE_HUSH_IF
		if (rword == RES_IF || rword == RES_ELIF)
			cond_code = rcode;
#endif
#if ENABLE_HUSH_LOOPS
		/* Beware of "while false; true; do ..."! */
		if (pi->next && pi->next->res_word == RES_DO) {
			if (rword == RES_WHILE) {
				if (rcode) {
					/* "while false; do...done" - exitcode 0 */
					G.last_exitcode = rcode = EXIT_SUCCESS;
					debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
					goto check_jobs_and_break;
				}
			}
			if (rword == RES_UNTIL) {
				if (!rcode) {
					debug_printf_exec(": until expr is true: breaking\n");
 check_jobs_and_break:
					checkjobs(NULL);
					break;
				}
			}
		}
#endif

 check_jobs_and_continue:
		checkjobs(NULL);
	} /* for (pi) */

#if ENABLE_HUSH_JOB
	G.run_list_level--;
#endif
#if ENABLE_HUSH_LOOPS
	if (loop_top)
		G.depth_of_loop--;
	free(for_list);
#endif
#if ENABLE_HUSH_CASE
	free(case_word);
#endif
	debug_leave();
	debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
	return rcode;
}

/* Select which version we will use */
static int run_and_free_list(struct pipe *pi)
{
	int rcode = 0;
	debug_printf_exec("run_and_free_list entered\n");
	if (!G.fake_mode) {
		debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
		rcode = run_list(pi);
	}
	/* free_pipe_list has the side effect of clearing memory.
	 * In the long run that function can be merged with run_list,
	 * but doing that now would hobble the debugging effort. */
	free_pipe_list(pi);
	debug_printf_exec("run_and_free_list return %d\n", rcode);
	return rcode;
}


static struct pipe *new_pipe(void)
{
	struct pipe *pi;
	pi = xzalloc(sizeof(struct pipe));
	/*pi->followup = 0; - deliberately invalid value */
	/*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
	return pi;
}

/* Command (member of a pipe) is complete, or we start a new pipe
 * if ctx->command is NULL.
 * No errors possible here.
 */
static int done_command(struct parse_context *ctx)
{
	/* The command is really already in the pipe structure, so
	 * advance the pipe counter and make a new, null command. */
	struct pipe *pi = ctx->pipe;
	struct command *command = ctx->command;

	if (command) {
		if (IS_NULL_CMD(command)) {
			debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
			goto clear_and_ret;
		}
		pi->num_cmds++;
		debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
		//debug_print_tree(ctx->list_head, 20);
	} else {
		debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
	}

	/* Only real trickiness here is that the uncommitted
	 * command structure is not counted in pi->num_cmds. */
	pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
	ctx->command = command = &pi->cmds[pi->num_cmds];
 clear_and_ret:
	memset(command, 0, sizeof(*command));
	return pi->num_cmds; /* used only for 0/nonzero check */
}

static void done_pipe(struct parse_context *ctx, pipe_style type)
{
	int not_null;

	debug_printf_parse("done_pipe entered, followup %d\n", type);
	/* Close previous command */
	not_null = done_command(ctx);
	ctx->pipe->followup = type;
#if HAS_KEYWORDS
	ctx->pipe->pi_inverted = ctx->ctx_inverted;
	ctx->ctx_inverted = 0;
	ctx->pipe->res_word = ctx->ctx_res_w;
#endif

	/* Without this check, even just <enter> on command line generates
	 * tree of three NOPs (!). Which is harmless but annoying.
	 * IOW: it is safe to do it unconditionally. */
	if (not_null
#if ENABLE_HUSH_IF
	 || ctx->ctx_res_w == RES_FI
#endif
#if ENABLE_HUSH_LOOPS
	 || ctx->ctx_res_w == RES_DONE
	 || ctx->ctx_res_w == RES_FOR
	 || ctx->ctx_res_w == RES_IN
#endif
#if ENABLE_HUSH_CASE
	 || ctx->ctx_res_w == RES_ESAC
#endif
	) {
		struct pipe *new_p;
		debug_printf_parse("done_pipe: adding new pipe: "
				"not_null:%d ctx->ctx_res_w:%d\n",
				not_null, ctx->ctx_res_w);
		new_p = new_pipe();
		ctx->pipe->next = new_p;
		ctx->pipe = new_p;
		/* RES_THEN, RES_DO etc are "sticky" -
		 * they remain set for pipes inside if/while.
		 * This is used to control execution.
		 * RES_FOR and RES_IN are NOT sticky (needed to support
		 * cases where variable or value happens to match a keyword):
		 */
#if ENABLE_HUSH_LOOPS
		if (ctx->ctx_res_w == RES_FOR
		 || ctx->ctx_res_w == RES_IN)
			ctx->ctx_res_w = RES_NONE;
#endif
#if ENABLE_HUSH_CASE
		if (ctx->ctx_res_w == RES_MATCH)
			ctx->ctx_res_w = RES_CASE_BODY;
		if (ctx->ctx_res_w == RES_CASE)
			ctx->ctx_res_w = RES_CASE_IN;
#endif
		ctx->command = NULL; /* trick done_command below */
		/* Create the memory for command, roughly:
		 * ctx->pipe->cmds = new struct command;
		 * ctx->command = &ctx->pipe->cmds[0];
		 */
		done_command(ctx);
		//debug_print_tree(ctx->list_head, 10);
	}
	debug_printf_parse("done_pipe return\n");
}

static void initialize_context(struct parse_context *ctx)
{
	memset(ctx, 0, sizeof(*ctx));
	ctx->pipe = ctx->list_head = new_pipe();
	/* Create the memory for command, roughly:
	 * ctx->pipe->cmds = new struct command;
	 * ctx->command = &ctx->pipe->cmds[0];
	 */
	done_command(ctx);
}

/* If a reserved word is found and processed, parse context is modified
 * and 1 is returned.
 */
#if HAS_KEYWORDS
struct reserved_combo {
	char literal[6];
	unsigned char res;
	unsigned char assignment_flag;
	int flag;
};
enum {
	FLAG_END   = (1 << RES_NONE ),
# if ENABLE_HUSH_IF
	FLAG_IF    = (1 << RES_IF   ),
	FLAG_THEN  = (1 << RES_THEN ),
	FLAG_ELIF  = (1 << RES_ELIF ),
	FLAG_ELSE  = (1 << RES_ELSE ),
	FLAG_FI    = (1 << RES_FI   ),
# endif
# if ENABLE_HUSH_LOOPS
	FLAG_FOR   = (1 << RES_FOR  ),
	FLAG_WHILE = (1 << RES_WHILE),
	FLAG_UNTIL = (1 << RES_UNTIL),
	FLAG_DO    = (1 << RES_DO   ),
	FLAG_DONE  = (1 << RES_DONE ),
	FLAG_IN    = (1 << RES_IN   ),
# endif
# if ENABLE_HUSH_CASE
	FLAG_MATCH = (1 << RES_MATCH),
	FLAG_ESAC  = (1 << RES_ESAC ),
# endif
	FLAG_START = (1 << RES_XXXX ),
};

static const struct reserved_combo* match_reserved_word(o_string *word)
{
	/* Mostly a list of accepted follow-up reserved words.
	 * FLAG_END means we are done with the sequence, and are ready
	 * to turn the compound list into a command.
	 * FLAG_START means the word must start a new compound list.
	 */
	static const struct reserved_combo reserved_list[] = {
# if ENABLE_HUSH_IF
		{ "!",     RES_NONE,  NOT_ASSIGNMENT , 0 },
		{ "if",    RES_IF,    WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
		{ "then",  RES_THEN,  WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
		{ "elif",  RES_ELIF,  WORD_IS_KEYWORD, FLAG_THEN },
		{ "else",  RES_ELSE,  WORD_IS_KEYWORD, FLAG_FI   },
		{ "fi",    RES_FI,    NOT_ASSIGNMENT , FLAG_END  },
# endif
# if ENABLE_HUSH_LOOPS
		{ "for",   RES_FOR,   NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
		{ "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
		{ "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
		{ "in",    RES_IN,    NOT_ASSIGNMENT , FLAG_DO   },
		{ "do",    RES_DO,    WORD_IS_KEYWORD, FLAG_DONE },
		{ "done",  RES_DONE,  NOT_ASSIGNMENT , FLAG_END  },
# endif
# if ENABLE_HUSH_CASE
		{ "case",  RES_CASE,  NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
		{ "esac",  RES_ESAC,  NOT_ASSIGNMENT , FLAG_END  },
# endif
	};
	const struct reserved_combo *r;

	for (r = reserved_list;	r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
		if (strcmp(word->data, r->literal) == 0)
			return r;
	}
	return NULL;
}
/* Return 0: not a keyword, 1: keyword
 */
static int reserved_word(o_string *word, struct parse_context *ctx)
{
# if ENABLE_HUSH_CASE
	static const struct reserved_combo reserved_match = {
		"",        RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
	};
# endif
	const struct reserved_combo *r;

	if (word->o_quoted)
		return 0;
	r = match_reserved_word(word);
	if (!r)
		return 0;

	debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
# if ENABLE_HUSH_CASE
	if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
		/* "case word IN ..." - IN part starts first MATCH part */
		r = &reserved_match;
	} else
# endif
	if (r->flag == 0) { /* '!' */
		if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
			syntax_error("! ! command");
			ctx->ctx_res_w = RES_SNTX;
		}
		ctx->ctx_inverted = 1;
		return 1;
	}
	if (r->flag & FLAG_START) {
		struct parse_context *old;

		old = xmalloc(sizeof(*old));
		debug_printf_parse("push stack %p\n", old);
		*old = *ctx;   /* physical copy */
		initialize_context(ctx);
		ctx->stack = old;
	} else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
		syntax_error_at(word->data);
		ctx->ctx_res_w = RES_SNTX;
		return 1;
	} else {
		/* "{...} fi" is ok. "{...} if" is not
		 * Example:
		 * if { echo foo; } then { echo bar; } fi */
		if (ctx->command->group)
			done_pipe(ctx, PIPE_SEQ);
	}

	ctx->ctx_res_w = r->res;
	ctx->old_flag = r->flag;
	word->o_assignment = r->assignment_flag;

	if (ctx->old_flag & FLAG_END) {
		struct parse_context *old;

		done_pipe(ctx, PIPE_SEQ);
		debug_printf_parse("pop stack %p\n", ctx->stack);
		old = ctx->stack;
		old->command->group = ctx->list_head;
		old->command->cmd_type = CMD_NORMAL;
# if !BB_MMU
		o_addstr(&old->as_string, ctx->as_string.data);
		o_free_unsafe(&ctx->as_string);
		old->command->group_as_string = xstrdup(old->as_string.data);
		debug_printf_parse("pop, remembering as:'%s'\n",
				old->command->group_as_string);
# endif
		*ctx = *old;   /* physical copy */
		free(old);
	}
	return 1;
}
#endif /* HAS_KEYWORDS */

/* Word is complete, look at it and update parsing context.
 * Normal return is 0. Syntax errors return 1.
 * Note: on return, word is reset, but not o_free'd!
 */
static int done_word(o_string *word, struct parse_context *ctx)
{
	struct command *command = ctx->command;

	debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
	if (word->length == 0 && word->o_quoted == 0) {
		debug_printf_parse("done_word return 0: true null, ignored\n");
		return 0;
	}

	if (ctx->pending_redirect) {
		/* We do not glob in e.g. >*.tmp case. bash seems to glob here
		 * only if run as "bash", not "sh" */
		/* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
		 * "2.7 Redirection
		 * ...the word that follows the redirection operator
		 * shall be subjected to tilde expansion, parameter expansion,
		 * command substitution, arithmetic expansion, and quote
		 * removal. Pathname expansion shall not be performed
		 * on the word by a non-interactive shell; an interactive
		 * shell may perform it, but shall do so only when
		 * the expansion would result in one word."
		 */
		ctx->pending_redirect->rd_filename = xstrdup(word->data);
		/* Cater for >\file case:
		 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
		 * Same with heredocs:
		 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
		 */
		if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
			unbackslash(ctx->pending_redirect->rd_filename);
			/* Is it <<"HEREDOC"? */
			if (word->o_quoted) {
				ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
			}
		}
		debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
		ctx->pending_redirect = NULL;
	} else {
		/* If this word wasn't an assignment, next ones definitely
		 * can't be assignments. Even if they look like ones. */
		if (word->o_assignment != DEFINITELY_ASSIGNMENT
		 && word->o_assignment != WORD_IS_KEYWORD
		) {
			word->o_assignment = NOT_ASSIGNMENT;
		} else {
			if (word->o_assignment == DEFINITELY_ASSIGNMENT)
				command->assignment_cnt++;
			word->o_assignment = MAYBE_ASSIGNMENT;
		}

#if HAS_KEYWORDS
# if ENABLE_HUSH_CASE
		if (ctx->ctx_dsemicolon
		 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
		) {
			/* already done when ctx_dsemicolon was set to 1: */
			/* ctx->ctx_res_w = RES_MATCH; */
			ctx->ctx_dsemicolon = 0;
		} else
# endif
		if (!command->argv /* if it's the first word... */
# if ENABLE_HUSH_LOOPS
		 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
		 && ctx->ctx_res_w != RES_IN
# endif
# if ENABLE_HUSH_CASE
		 && ctx->ctx_res_w != RES_CASE
# endif
		) {
			debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
			if (reserved_word(word, ctx)) {
				o_reset_to_empty_unquoted(word);
				debug_printf_parse("done_word return %d\n",
						(ctx->ctx_res_w == RES_SNTX));
				return (ctx->ctx_res_w == RES_SNTX);
			}
# ifdef CMD_SINGLEWORD_NOGLOB_COND
			if (strcmp(word->data, "export") == 0
#  if ENABLE_HUSH_LOCAL
			 || strcmp(word->data, "local") == 0
#  endif
			) {
				command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
			} else
# endif
# if ENABLE_HUSH_BASH_COMPAT
			if (strcmp(word->data, "[[") == 0) {
				command->cmd_type = CMD_SINGLEWORD_NOGLOB;
			}
			/* fall through */
# endif
		}
#endif
		if (command->group) {
			/* "{ echo foo; } echo bar" - bad */
			syntax_error_at(word->data);
			debug_printf_parse("done_word return 1: syntax error, "
					"groups and arglists don't mix\n");
			return 1;
		}
		if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
		 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
		 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
		 /* (otherwise it's known to be not empty and is already safe) */
		) {
			/* exclude "$@" - it can expand to no word despite "" */
			char *p = word->data;
			while (p[0] == SPECIAL_VAR_SYMBOL
			    && (p[1] & 0x7f) == '@'
			    && p[2] == SPECIAL_VAR_SYMBOL
			) {
				p += 3;
			}
			if (p == word->data || p[0] != '\0') {
				/* saw no "$@", or not only "$@" but some
				 * real text is there too */
				/* insert "empty variable" reference, this makes
				 * e.g. "", $empty"" etc to not disappear */
				o_addchr(word, SPECIAL_VAR_SYMBOL);
				o_addchr(word, SPECIAL_VAR_SYMBOL);
			}
		}
		command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
		debug_print_strings("word appended to argv", command->argv);
	}

#if ENABLE_HUSH_LOOPS
	if (ctx->ctx_res_w == RES_FOR) {
		if (word->o_quoted
		 || !is_well_formed_var_name(command->argv[0], '\0')
		) {
			/* bash says just "not a valid identifier" */
			syntax_error("not a valid identifier in for");
			return 1;
		}
		/* Force FOR to have just one word (variable name) */
		/* NB: basically, this makes hush see "for v in ..."
		 * syntax as if it is "for v; in ...". FOR and IN become
		 * two pipe structs in parse tree. */
		done_pipe(ctx, PIPE_SEQ);
	}
#endif
#if ENABLE_HUSH_CASE
	/* Force CASE to have just one word */
	if (ctx->ctx_res_w == RES_CASE) {
		done_pipe(ctx, PIPE_SEQ);
	}
#endif

	o_reset_to_empty_unquoted(word);

	debug_printf_parse("done_word return 0\n");
	return 0;
}


/* Peek ahead in the input to find out if we have a "&n" construct,
 * as in "2>&1", that represents duplicating a file descriptor.
 * Return:
 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
 * REDIRFD_SYNTAX_ERR if syntax error,
 * REDIRFD_TO_FILE if no & was seen,
 * or the number found.
 */
#if BB_MMU
#define parse_redir_right_fd(as_string, input) \
	parse_redir_right_fd(input)
#endif
static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
{
	int ch, d, ok;

	ch = i_peek(input);
	if (ch != '&')
		return REDIRFD_TO_FILE;

	ch = i_getch(input);  /* get the & */
	nommu_addchr(as_string, ch);
	ch = i_peek(input);
	if (ch == '-') {
		ch = i_getch(input);
		nommu_addchr(as_string, ch);
		return REDIRFD_CLOSE;
	}
	d = 0;
	ok = 0;
	while (ch != EOF && isdigit(ch)) {
		d = d*10 + (ch-'0');
		ok = 1;
		ch = i_getch(input);
		nommu_addchr(as_string, ch);
		ch = i_peek(input);
	}
	if (ok) return d;

//TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)

	bb_error_msg("ambiguous redirect");
	return REDIRFD_SYNTAX_ERR;
}

/* Return code is 0 normal, 1 if a syntax error is detected
 */
static int parse_redirect(struct parse_context *ctx,
		int fd,
		redir_type style,
		struct in_str *input)
{
	struct command *command = ctx->command;
	struct redir_struct *redir;
	struct redir_struct **redirp;
	int dup_num;

	dup_num = REDIRFD_TO_FILE;
	if (style != REDIRECT_HEREDOC) {
		/* Check for a '>&1' type redirect */
		dup_num = parse_redir_right_fd(&ctx->as_string, input);
		if (dup_num == REDIRFD_SYNTAX_ERR)
			return 1;
	} else {
		int ch = i_peek(input);
		dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
		if (dup_num) { /* <<-... */
			ch = i_getch(input);
			nommu_addchr(&ctx->as_string, ch);
			ch = i_peek(input);
		}
	}

	if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
		int ch = i_peek(input);
		if (ch == '|') {
			/* >|FILE redirect ("clobbering" >).
			 * Since we do not support "set -o noclobber" yet,
			 * >| and > are the same for now. Just eat |.
			 */
			ch = i_getch(input);
			nommu_addchr(&ctx->as_string, ch);
		}
	}

	/* Create a new redir_struct and append it to the linked list */
	redirp = &command->redirects;
	while ((redir = *redirp) != NULL) {
		redirp = &(redir->next);
	}
	*redirp = redir = xzalloc(sizeof(*redir));
	/* redir->next = NULL; */
	/* redir->rd_filename = NULL; */
	redir->rd_type = style;
	redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;

	debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
				redir_table[style].descrip);

	redir->rd_dup = dup_num;
	if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
		/* Erik had a check here that the file descriptor in question
		 * is legit; I postpone that to "run time"
		 * A "-" representation of "close me" shows up as a -3 here */
		debug_printf_parse("duplicating redirect '%d>&%d'\n",
				redir->rd_fd, redir->rd_dup);
	} else {
		/* Set ctx->pending_redirect, so we know what to do at the
		 * end of the next parsed word. */
		ctx->pending_redirect = redir;
	}
	return 0;
}

/* If a redirect is immediately preceded by a number, that number is
 * supposed to tell which file descriptor to redirect.  This routine
 * looks for such preceding numbers.  In an ideal world this routine
 * needs to handle all the following classes of redirects...
 *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
 *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
 *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
 *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
 *
 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
 * "2.7 Redirection
 * ... If n is quoted, the number shall not be recognized as part of
 * the redirection expression. For example:
 * echo \2>a
 * writes the character 2 into file a"
 * We are getting it right by setting ->o_quoted on any \<char>
 *
 * A -1 return means no valid number was found,
 * the caller should use the appropriate default for this redirection.
 */
static int redirect_opt_num(o_string *o)
{
	int num;

	if (o->data == NULL)
		return -1;
	num = bb_strtou(o->data, NULL, 10);
	if (errno || num < 0)
		return -1;
	o_reset_to_empty_unquoted(o);
	return num;
}

#if BB_MMU
#define fetch_till_str(as_string, input, word, skip_tabs) \
	fetch_till_str(input, word, skip_tabs)
#endif
static char *fetch_till_str(o_string *as_string,
		struct in_str *input,
		const char *word,
		int skip_tabs)
{
	o_string heredoc = NULL_O_STRING;
	int past_EOL = 0;
	int ch;

	goto jump_in;
	while (1) {
		ch = i_getch(input);
		nommu_addchr(as_string, ch);
		if (ch == '\n') {
			if (strcmp(heredoc.data + past_EOL, word) == 0) {
				heredoc.data[past_EOL] = '\0';
				debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
				return heredoc.data;
			}
			do {
				o_addchr(&heredoc, ch);
				past_EOL = heredoc.length;
 jump_in:
				do {
					ch = i_getch(input);
					nommu_addchr(as_string, ch);
				} while (skip_tabs && ch == '\t');
			} while (ch == '\n');
		}
		if (ch == EOF) {
			o_free_unsafe(&heredoc);
			return NULL;
		}
		o_addchr(&heredoc, ch);
		nommu_addchr(as_string, ch);
	}
}

/* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
 * and load them all. There should be exactly heredoc_cnt of them.
 */
static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
{
	struct pipe *pi = ctx->list_head;

	while (pi && heredoc_cnt) {
		int i;
		struct command *cmd = pi->cmds;

		debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
				pi->num_cmds,
				cmd->argv ? cmd->argv[0] : "NONE");
		for (i = 0; i < pi->num_cmds; i++) {
			struct redir_struct *redir = cmd->redirects;

			debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
					i, cmd->argv ? cmd->argv[0] : "NONE");
			while (redir) {
				if (redir->rd_type == REDIRECT_HEREDOC) {
					char *p;

					redir->rd_type = REDIRECT_HEREDOC2;
					/* redir->rd_dup is (ab)used to indicate <<- */
					p = fetch_till_str(&ctx->as_string, input,
						redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
					if (!p) {
						syntax_error("unexpected EOF in here document");
						return 1;
					}
					free(redir->rd_filename);
					redir->rd_filename = p;
					heredoc_cnt--;
				}
				redir = redir->next;
			}
			cmd++;
		}
		pi = pi->next;
	}
#if 0
	/* Should be 0. If it isn't, it's a parse error */
	if (heredoc_cnt)
		bb_error_msg_and_die("heredoc BUG 2");
#endif
	return 0;
}


#if ENABLE_HUSH_TICK
static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
{
	pid_t pid;
	int channel[2];
# if !BB_MMU
	char **to_free = NULL;
# endif

	xpipe(channel);
	pid = BB_MMU ? xfork() : xvfork();
	if (pid == 0) { /* child */
		disable_restore_tty_pgrp_on_exit();
		/* Process substitution is not considered to be usual
		 * 'command execution'.
		 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
		 */
		bb_signals(0
			+ (1 << SIGTSTP)
			+ (1 << SIGTTIN)
			+ (1 << SIGTTOU)
			, SIG_IGN);
		CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
		close(channel[0]); /* NB: close _first_, then move fd! */
		xmove_fd(channel[1], 1);
		/* Prevent it from trying to handle ctrl-z etc */
		IF_HUSH_JOB(G.run_list_level = 1;)
		/* Awful hack for `trap` or $(trap).
		 *
		 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
		 * contains an example where "trap" is executed in a subshell:
		 *
		 * save_traps=$(trap)
		 * ...
		 * eval "$save_traps"
		 *
		 * Standard does not say that "trap" in subshell shall print
		 * parent shell's traps. It only says that its output
		 * must have suitable form, but then, in the above example
		 * (which is not supposed to be normative), it implies that.
		 *
		 * bash (and probably other shell) does implement it
		 * (traps are reset to defaults, but "trap" still shows them),
		 * but as a result, "trap" logic is hopelessly messed up:
		 *
		 * # trap
		 * trap -- 'echo Ho' SIGWINCH  <--- we have a handler
		 * # (trap)        <--- trap is in subshell - no output (correct, traps are reset)
		 * # true | trap   <--- trap is in subshell - no output (ditto)
		 * # echo `true | trap`    <--- in subshell - output (but traps are reset!)
		 * trap -- 'echo Ho' SIGWINCH
		 * # echo `(trap)`         <--- in subshell in subshell - output
		 * trap -- 'echo Ho' SIGWINCH
		 * # echo `true | (trap)`  <--- in subshell in subshell in subshell - output!
		 * trap -- 'echo Ho' SIGWINCH
		 *
		 * The rules when to forget and when to not forget traps
		 * get really complex and nonsensical.
		 *
		 * Our solution: ONLY bare $(trap) or `trap` is special.
		 */
		s = skip_whitespace(s);
		if (strncmp(s, "trap", 4) == 0 && (*skip_whitespace(s + 4) == '\0'))
		{
			static const char *const argv[] = { NULL, NULL };
			builtin_trap((char**)argv);
			exit(0); /* not _exit() - we need to fflush */
		}
# if BB_MMU
		reset_traps_to_defaults();
		parse_and_run_string(s);
		_exit(G.last_exitcode);
# else
	/* We re-execute after vfork on NOMMU. This makes this script safe:
	 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
	 * huge=`cat BIG` # was blocking here forever
	 * echo OK
	 */
		re_execute_shell(&to_free,
				s,
				G.global_argv[0],
				G.global_argv + 1,
				NULL);
# endif
	}

	/* parent */
	*pid_p = pid;
# if ENABLE_HUSH_FAST
	G.count_SIGCHLD++;
//bb_error_msg("[%d] fork in generate_stream_from_string: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
# endif
	enable_restore_tty_pgrp_on_exit();
# if !BB_MMU
	free(to_free);
# endif
	close(channel[1]);
	close_on_exec_on(channel[0]);
	return xfdopen_for_read(channel[0]);
}

/* Return code is exit status of the process that is run. */
static int process_command_subs(o_string *dest, const char *s)
{
	FILE *fp;
	struct in_str pipe_str;
	pid_t pid;
	int status, ch, eol_cnt;

	fp = generate_stream_from_string(s, &pid);

	/* Now send results of command back into original context */
	setup_file_in_str(&pipe_str, fp);
	eol_cnt = 0;
	while ((ch = i_getch(&pipe_str)) != EOF) {
		if (ch == '\n') {
			eol_cnt++;
			continue;
		}
		while (eol_cnt) {
			o_addchr(dest, '\n');
			eol_cnt--;
		}
		o_addQchr(dest, ch);
	}

	debug_printf("done reading from `cmd` pipe, closing it\n");
	fclose(fp);
	/* We need to extract exitcode. Test case
	 * "true; echo `sleep 1; false` $?"
	 * should print 1 */
	safe_waitpid(pid, &status, 0);
	debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
	return WEXITSTATUS(status);
}
#endif /* ENABLE_HUSH_TICK */

#if !ENABLE_HUSH_FUNCTIONS
#define parse_group(dest, ctx, input, ch) \
	parse_group(ctx, input, ch)
#endif
static int parse_group(o_string *dest, struct parse_context *ctx,
	struct in_str *input, int ch)
{
	/* dest contains characters seen prior to ( or {.
	 * Typically it's empty, but for function defs,
	 * it contains function name (without '()'). */
	struct pipe *pipe_list;
	int endch;
	struct command *command = ctx->command;

	debug_printf_parse("parse_group entered\n");
#if ENABLE_HUSH_FUNCTIONS
	if (ch == '(' && !dest->o_quoted) {
		if (dest->length)
			if (done_word(dest, ctx))
				return 1;
		if (!command->argv)
			goto skip; /* (... */
		if (command->argv[1]) { /* word word ... (... */
			syntax_error_unexpected_ch('(');
			return 1;
		}
		/* it is "word(..." or "word (..." */
		do
			ch = i_getch(input);
		while (ch == ' ' || ch == '\t');
		if (ch != ')') {
			syntax_error_unexpected_ch(ch);
			return 1;
		}
		nommu_addchr(&ctx->as_string, ch);
		do
			ch = i_getch(input);
		while (ch == ' ' || ch == '\t' || ch == '\n');
		if (ch != '{') {
			syntax_error_unexpected_ch(ch);
			return 1;
		}
		nommu_addchr(&ctx->as_string, ch);
		command->cmd_type = CMD_FUNCDEF;
		goto skip;
	}
#endif

#if 0 /* Prevented by caller */
	if (command->argv /* word [word]{... */
	 || dest->length /* word{... */
	 || dest->o_quoted /* ""{... */
	) {
		syntax_error(NULL);
		debug_printf_parse("parse_group return 1: "
			"syntax error, groups and arglists don't mix\n");
		return 1;
	}
#endif

#if ENABLE_HUSH_FUNCTIONS
 skip:
#endif
	endch = '}';
	if (ch == '(') {
		endch = ')';
		command->cmd_type = CMD_SUBSHELL;
	} else {
		/* bash does not allow "{echo...", requires whitespace */
		ch = i_getch(input);
		if (ch != ' ' && ch != '\t' && ch != '\n') {
			syntax_error_unexpected_ch(ch);
			return 1;
		}
		nommu_addchr(&ctx->as_string, ch);
	}

	{
#if BB_MMU
# define as_string NULL
#else
		char *as_string = NULL;
#endif
		pipe_list = parse_stream(&as_string, input, endch);
#if !BB_MMU
		if (as_string)
			o_addstr(&ctx->as_string, as_string);
#endif
		/* empty ()/{} or parse error? */
		if (!pipe_list || pipe_list == ERR_PTR) {
			/* parse_stream already emitted error msg */
			if (!BB_MMU)
				free(as_string);
			debug_printf_parse("parse_group return 1: "
				"parse_stream returned %p\n", pipe_list);
			return 1;
		}
		command->group = pipe_list;
#if !BB_MMU
		as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
		command->group_as_string = as_string;
		debug_printf_parse("end of group, remembering as:'%s'\n",
				command->group_as_string);
#endif
#undef as_string
	}
	debug_printf_parse("parse_group return 0\n");
	return 0;
	/* command remains "open", available for possible redirects */
}

#if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
/* Subroutines for copying $(...) and `...` things */
static void add_till_backquote(o_string *dest, struct in_str *input);
/* '...' */
static void add_till_single_quote(o_string *dest, struct in_str *input)
{
	while (1) {
		int ch = i_getch(input);
		if (ch == EOF) {
			syntax_error_unterm_ch('\'');
			/*xfunc_die(); - redundant */
		}
		if (ch == '\'')
			return;
		o_addchr(dest, ch);
	}
}
/* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
static void add_till_double_quote(o_string *dest, struct in_str *input)
{
	while (1) {
		int ch = i_getch(input);
		if (ch == EOF) {
			syntax_error_unterm_ch('"');
			/*xfunc_die(); - redundant */
		}
		if (ch == '"')
			return;
		if (ch == '\\') {  /* \x. Copy both chars. */
			o_addchr(dest, ch);
			ch = i_getch(input);
		}
		o_addchr(dest, ch);
		if (ch == '`') {
			add_till_backquote(dest, input);
			o_addchr(dest, ch);
			continue;
		}
		//if (ch == '$') ...
	}
}
/* Process `cmd` - copy contents until "`" is seen. Complicated by
 * \` quoting.
 * "Within the backquoted style of command substitution, backslash
 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
 * The search for the matching backquote shall be satisfied by the first
 * backquote found without a preceding backslash; during this search,
 * if a non-escaped backquote is encountered within a shell comment,
 * a here-document, an embedded command substitution of the $(command)
 * form, or a quoted string, undefined results occur. A single-quoted
 * or double-quoted string that begins, but does not end, within the
 * "`...`" sequence produces undefined results."
 * Example                               Output
 * echo `echo '\'TEST\`echo ZZ\`BEST`    \TESTZZBEST
 */
static void add_till_backquote(o_string *dest, struct in_str *input)
{
	while (1) {
		int ch = i_getch(input);
		if (ch == EOF) {
			syntax_error_unterm_ch('`');
			/*xfunc_die(); - redundant */
		}
		if (ch == '`')
			return;
		if (ch == '\\') {
			/* \x. Copy both chars unless it is \` */
			int ch2 = i_getch(input);
			if (ch2 == EOF) {
				syntax_error_unterm_ch('`');
				/*xfunc_die(); - redundant */
			}
			if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
				o_addchr(dest, ch);
			ch = ch2;
		}
		o_addchr(dest, ch);
	}
}
/* Process $(cmd) - copy contents until ")" is seen. Complicated by
 * quoting and nested ()s.
 * "With the $(command) style of command substitution, all characters
 * following the open parenthesis to the matching closing parenthesis
 * constitute the command. Any valid shell script can be used for command,
 * except a script consisting solely of redirections which produces
 * unspecified results."
 * Example                              Output
 * echo $(echo '(TEST)' BEST)           (TEST) BEST
 * echo $(echo 'TEST)' BEST)            TEST) BEST
 * echo $(echo \(\(TEST\) BEST)         ((TEST) BEST
 *
 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
 * can contain arbitrary constructs, just like $(cmd).
 * In bash compat mode, it needs to also be able to stop on '}' or ':'
 * for ${var:N[:M]} parsing.
 */
#define DOUBLE_CLOSE_CHAR_FLAG 0x80
static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
{
	int ch;
	char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
#if ENABLE_HUSH_BASH_COMPAT
	char end_char2 = end_ch >> 8;
#endif
	end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);

	while (1) {
		ch = i_getch(input);
		if (ch == EOF) {
			syntax_error_unterm_ch(end_ch);
			/*xfunc_die(); - redundant */
		}
		if (ch == end_ch  IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
			if (!dbl)
				break;
			/* we look for closing )) of $((EXPR)) */
			if (i_peek(input) == end_ch) {
				i_getch(input); /* eat second ')' */
				break;
			}
		}
		o_addchr(dest, ch);
		if (ch == '(' || ch == '{') {
			ch = (ch == '(' ? ')' : '}');
			add_till_closing_bracket(dest, input, ch);
			o_addchr(dest, ch);
			continue;
		}
		if (ch == '\'') {
			add_till_single_quote(dest, input);
			o_addchr(dest, ch);
			continue;
		}
		if (ch == '"') {
			add_till_double_quote(dest, input);
			o_addchr(dest, ch);
			continue;
		}
		if (ch == '`') {
			add_till_backquote(dest, input);
			o_addchr(dest, ch);
			continue;
		}
		if (ch == '\\') {
			/* \x. Copy verbatim. Important for  \(, \) */
			ch = i_getch(input);
			if (ch == EOF) {
				syntax_error_unterm_ch(')');
				/*xfunc_die(); - redundant */
			}
			o_addchr(dest, ch);
			continue;
		}
	}
	return ch;
}
#endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */

/* Return code: 0 for OK, 1 for syntax error */
#if BB_MMU
#define parse_dollar(as_string, dest, input) \
	parse_dollar(dest, input)
#define as_string NULL
#endif
static int parse_dollar(o_string *as_string,
		o_string *dest,
		struct in_str *input)
{
	int ch = i_peek(input);  /* first character after the $ */
	unsigned char quote_mask = dest->o_escape ? 0x80 : 0;

	debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
	if (isalpha(ch)) {
		ch = i_getch(input);
		nommu_addchr(as_string, ch);
 make_var:
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
		while (1) {
			debug_printf_parse(": '%c'\n", ch);
			o_addchr(dest, ch | quote_mask);
			quote_mask = 0;
			ch = i_peek(input);
			if (!isalnum(ch) && ch != '_')
				break;
			ch = i_getch(input);
			nommu_addchr(as_string, ch);
		}
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
	} else if (isdigit(ch)) {
 make_one_char_var:
		ch = i_getch(input);
		nommu_addchr(as_string, ch);
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
		debug_printf_parse(": '%c'\n", ch);
		o_addchr(dest, ch | quote_mask);
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
	} else switch (ch) {
	case '$': /* pid */
	case '!': /* last bg pid */
	case '?': /* last exit code */
	case '#': /* number of args */
	case '*': /* args */
	case '@': /* args */
		goto make_one_char_var;
	case '{': {
		o_addchr(dest, SPECIAL_VAR_SYMBOL);

		ch = i_getch(input); /* eat '{' */
		nommu_addchr(as_string, ch);

		ch = i_getch(input); /* first char after '{' */
		nommu_addchr(as_string, ch);
		/* It should be ${?}, or ${#var},
		 * or even ${?+subst} - operator acting on a special variable,
		 * or the beginning of variable name.
		 */
		if (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) { /* not one of those */
 bad_dollar_syntax:
			syntax_error_unterm_str("${name}");
			debug_printf_parse("parse_dollar return 1: unterminated ${name}\n");
			return 1;
		}
		ch |= quote_mask;

		/* It's possible to just call add_till_closing_bracket() at this point.
		 * However, this regresses some of our testsuite cases
		 * which check invalid constructs like ${%}.
		 * Oh well... let's check that the var name part is fine... */

		while (1) {
			unsigned pos;

			o_addchr(dest, ch);
			debug_printf_parse(": '%c'\n", ch);

			ch = i_getch(input);
			nommu_addchr(as_string, ch);
			if (ch == '}')
				break;

			if (!isalnum(ch) && ch != '_') {
				unsigned end_ch;
				unsigned char last_ch;
				/* handle parameter expansions
				 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
				 */
				if (!strchr("%#:-=+?", ch)) /* ${var<bad_char>... */
					goto bad_dollar_syntax;
				o_addchr(dest, ch);

				/* Eat everything until closing '}' (or ':') */
				end_ch = '}';
				if (ENABLE_HUSH_BASH_COMPAT
				 && ch == ':'
				 && !strchr("%#:-=+?"+3, i_peek(input))
				) {
					/* It's ${var:N[:M]} thing */
					end_ch = '}' * 0x100 + ':';
				}
 again:
				if (!BB_MMU)
					pos = dest->length;
				last_ch = add_till_closing_bracket(dest, input, end_ch);
				if (as_string) {
					o_addstr(as_string, dest->data + pos);
					o_addchr(as_string, last_ch);
				}

				if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
					/* close the first block: */
					o_addchr(dest, SPECIAL_VAR_SYMBOL);
					/* while parsing N from ${var:N[:M]}... */
					if ((end_ch & 0xff) == last_ch) {
						/* ...got ':' - parse the rest */
						end_ch = '}';
						goto again;
					}
					/* ...got '}', not ':' - it's ${var:N}! emulate :999999999 */
					o_addstr(dest, "999999999");
				}
				break;
			}
		}
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
		break;
	}
#if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
	case '(': {
		unsigned pos;

		ch = i_getch(input);
		nommu_addchr(as_string, ch);
# if ENABLE_SH_MATH_SUPPORT
		if (i_peek(input) == '(') {
			ch = i_getch(input);
			nommu_addchr(as_string, ch);
			o_addchr(dest, SPECIAL_VAR_SYMBOL);
			o_addchr(dest, /*quote_mask |*/ '+');
			if (!BB_MMU)
				pos = dest->length;
			add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
			if (as_string) {
				o_addstr(as_string, dest->data + pos);
				o_addchr(as_string, ')');
				o_addchr(as_string, ')');
			}
			o_addchr(dest, SPECIAL_VAR_SYMBOL);
			break;
		}
# endif
# if ENABLE_HUSH_TICK
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
		o_addchr(dest, quote_mask | '`');
		if (!BB_MMU)
			pos = dest->length;
		add_till_closing_bracket(dest, input, ')');
		if (as_string) {
			o_addstr(as_string, dest->data + pos);
			o_addchr(as_string, ')');
		}
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
# endif
		break;
	}
#endif
	case '_':
		ch = i_getch(input);
		nommu_addchr(as_string, ch);
		ch = i_peek(input);
		if (isalnum(ch)) { /* it's $_name or $_123 */
			ch = '_';
			goto make_var;
		}
		/* else: it's $_ */
	/* TODO: $_ and $-: */
	/* $_ Shell or shell script name; or last argument of last command
	 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
	 * but in command's env, set to full pathname used to invoke it */
	/* $- Option flags set by set builtin or shell options (-i etc) */
	default:
		o_addQchr(dest, '$');
	}
	debug_printf_parse("parse_dollar return 0\n");
	return 0;
#undef as_string
}

#if BB_MMU
#define parse_stream_dquoted(as_string, dest, input, dquote_end) \
	parse_stream_dquoted(dest, input, dquote_end)
#define as_string NULL
#endif
static int parse_stream_dquoted(o_string *as_string,
		o_string *dest,
		struct in_str *input,
		int dquote_end)
{
	int ch;
	int next;

 again:
	ch = i_getch(input);
	if (ch != EOF)
		nommu_addchr(as_string, ch);
	if (ch == dquote_end) { /* may be only '"' or EOF */
		if (dest->o_assignment == NOT_ASSIGNMENT)
			dest->o_escape ^= 1;
		debug_printf_parse("parse_stream_dquoted return 0\n");
		return 0;
	}
	/* note: can't move it above ch == dquote_end check! */
	if (ch == EOF) {
		syntax_error_unterm_ch('"');
		/*xfunc_die(); - redundant */
	}
	next = '\0';
	if (ch != '\n') {
		next = i_peek(input);
	}
	debug_printf_parse("\" ch=%c (%d) escape=%d\n",
					ch, ch, dest->o_escape);
	if (ch == '\\') {
		if (next == EOF) {
			syntax_error("\\<eof>");
			xfunc_die();
		}
		/* bash:
		 * "The backslash retains its special meaning [in "..."]
		 * only when followed by one of the following characters:
		 * $, `, ", \, or <newline>.  A double quote may be quoted
		 * within double quotes by preceding it with a backslash."
		 */
		if (strchr("$`\"\\\n", next) != NULL) {
			ch = i_getch(input);
			if (ch != '\n') {
				o_addqchr(dest, ch);
				nommu_addchr(as_string, ch);
			}
		} else {
			o_addqchr(dest, '\\');
			nommu_addchr(as_string, '\\');
		}
		goto again;
	}
	if (ch == '$') {
		if (parse_dollar(as_string, dest, input) != 0) {
			debug_printf_parse("parse_stream_dquoted return 1: "
					"parse_dollar returned non-0\n");
			return 1;
		}
		goto again;
	}
#if ENABLE_HUSH_TICK
	if (ch == '`') {
		//unsigned pos = dest->length;
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
		o_addchr(dest, 0x80 | '`');
		add_till_backquote(dest, input);
		o_addchr(dest, SPECIAL_VAR_SYMBOL);
		//debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
		goto again;
	}
#endif
	o_addQchr(dest, ch);
	if (ch == '='
	 && (dest->o_assignment == MAYBE_ASSIGNMENT
	    || dest->o_assignment == WORD_IS_KEYWORD)
	 && is_well_formed_var_name(dest->data, '=')
	) {
		dest->o_assignment = DEFINITELY_ASSIGNMENT;
	}
	goto again;
#undef as_string
}

/*
 * Scan input until EOF or end_trigger char.
 * Return a list of pipes to execute, or NULL on EOF
 * or if end_trigger character is met.
 * On syntax error, exit is shell is not interactive,
 * reset parsing machinery and start parsing anew,
 * or return ERR_PTR.
 */
static struct pipe *parse_stream(char **pstring,
		struct in_str *input,
		int end_trigger)
{
	struct parse_context ctx;
	o_string dest = NULL_O_STRING;
	int is_in_dquote;
	int heredoc_cnt;

	/* Double-quote state is handled in the state variable is_in_dquote.
	 * A single-quote triggers a bypass of the main loop until its mate is
	 * found.  When recursing, quote state is passed in via dest->o_escape.
	 */
	debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
			end_trigger ? end_trigger : 'X');
	debug_enter();

	/* If very first arg is "" or '', dest.data may end up NULL.
	 * Preventing this: */
	o_addchr(&dest, '\0');
	dest.length = 0;

	G.ifs = get_local_var_value("IFS");
	if (G.ifs == NULL)
		G.ifs = defifs;

 reset:
#if ENABLE_HUSH_INTERACTIVE
	input->promptmode = 0; /* PS1 */
#endif
	/* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
	initialize_context(&ctx);
	is_in_dquote = 0;
	heredoc_cnt = 0;
	while (1) {
		const char *is_ifs;
		const char *is_special;
		int ch;
		int next;
		int redir_fd;
		redir_type redir_style;

		if (is_in_dquote) {
			/* dest.o_quoted = 1; - already is (see below) */
			if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
				goto parse_error;
			}
			/* We reached closing '"' */
			is_in_dquote = 0;
		}
		ch = i_getch(input);
		debug_printf_parse(": ch=%c (%d) escape=%d\n",
						ch, ch, dest.o_escape);
		if (ch == EOF) {
			struct pipe *pi;

			if (heredoc_cnt) {
				syntax_error_unterm_str("here document");
				goto parse_error;
			}
			/* end_trigger == '}' case errors out earlier,
			 * checking only ')' */
			if (end_trigger == ')') {
				syntax_error_unterm_ch('('); /* exits */
				/* goto parse_error; */
			}

			if (done_word(&dest, &ctx)) {
				goto parse_error;
			}
			o_free(&dest);
			done_pipe(&ctx, PIPE_SEQ);
			pi = ctx.list_head;
			/* If we got nothing... */
			/* (this makes bare "&" cmd a no-op.
			 * bash says: "syntax error near unexpected token '&'") */
			if (pi->num_cmds == 0
			    IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
			) {
				free_pipe_list(pi);
				pi = NULL;
			}
#if !BB_MMU
			debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
			if (pstring)
				*pstring = ctx.as_string.data;
			else
				o_free_unsafe(&ctx.as_string);
#endif
			debug_leave();
			debug_printf_parse("parse_stream return %p\n", pi);
			return pi;
		}
		nommu_addchr(&ctx.as_string, ch);

		next = '\0';
		if (ch != '\n')
			next = i_peek(input);

		is_special = "{}<>;&|()#'" /* special outside of "str" */
				"\\$\"" IF_HUSH_TICK("`"); /* always special */
		/* Are { and } special here? */
		if (ctx.command->argv /* word [word]{... - non-special */
		 || dest.length       /* word{... - non-special */
		 || dest.o_quoted     /* ""{... - non-special */
		 || (next != ';'            /* }; - special */
		    && next != ')'          /* }) - special */
		    && next != '&'          /* }& and }&& ... - special */
		    && next != '|'          /* }|| ... - special */
		    && !strchr(G.ifs, next) /* {word - non-special */
		    )
		) {
			/* They are not special, skip "{}" */
			is_special += 2;
		}
		is_special = strchr(is_special, ch);
		is_ifs = strchr(G.ifs, ch);

		if (!is_special && !is_ifs) { /* ordinary char */
 ordinary_char:
			o_addQchr(&dest, ch);
			if ((dest.o_assignment == MAYBE_ASSIGNMENT
			    || dest.o_assignment == WORD_IS_KEYWORD)
			 && ch == '='
			 && is_well_formed_var_name(dest.data, '=')
			) {
				dest.o_assignment = DEFINITELY_ASSIGNMENT;
			}
			continue;
		}

		if (is_ifs) {
			if (done_word(&dest, &ctx)) {
				goto parse_error;
			}
			if (ch == '\n') {
#if ENABLE_HUSH_CASE
				/* "case ... in <newline> word) ..." -
				 * newlines are ignored (but ';' wouldn't be) */
				if (ctx.command->argv == NULL
				 && ctx.ctx_res_w == RES_MATCH
				) {
					continue;
				}
#endif
				/* Treat newline as a command separator. */
				done_pipe(&ctx, PIPE_SEQ);
				debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
				if (heredoc_cnt) {
					if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
						goto parse_error;
					}
					heredoc_cnt = 0;
				}
				dest.o_assignment = MAYBE_ASSIGNMENT;
				ch = ';';
				/* note: if (is_ifs) continue;
				 * will still trigger for us */
			}
		}

		/* "cmd}" or "cmd }..." without semicolon or &:
		 * } is an ordinary char in this case, even inside { cmd; }
		 * Pathological example: { ""}; } should exec "}" cmd
		 */
		if (ch == '}') {
			if (!IS_NULL_CMD(ctx.command) /* cmd } */
			 || dest.length != 0 /* word} */
			 || dest.o_quoted    /* ""} */
			) {
				goto ordinary_char;
			}
			if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
				goto skip_end_trigger;
			/* else: } does terminate a group */
		}

		if (end_trigger && end_trigger == ch
		 && (ch != ';' || heredoc_cnt == 0)
#if ENABLE_HUSH_CASE
		 && (ch != ')'
		    || ctx.ctx_res_w != RES_MATCH
		    || (!dest.o_quoted && strcmp(dest.data, "esac") == 0)
		    )
#endif
		) {
			if (heredoc_cnt) {
				/* This is technically valid:
				 * { cat <<HERE; }; echo Ok
				 * heredoc
				 * heredoc
				 * HERE
				 * but we don't support this.
				 * We require heredoc to be in enclosing {}/(),
				 * if any.
				 */
				syntax_error_unterm_str("here document");
				goto parse_error;
			}
			if (done_word(&dest, &ctx)) {
				goto parse_error;
			}
			done_pipe(&ctx, PIPE_SEQ);
			dest.o_assignment = MAYBE_ASSIGNMENT;
			/* Do we sit outside of any if's, loops or case's? */
			if (!HAS_KEYWORDS
			 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
			) {
				o_free(&dest);
#if !BB_MMU
				debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
				if (pstring)
					*pstring = ctx.as_string.data;
				else
					o_free_unsafe(&ctx.as_string);
#endif
				debug_leave();
				debug_printf_parse("parse_stream return %p: "
						"end_trigger char found\n",
						ctx.list_head);
				return ctx.list_head;
			}
		}
 skip_end_trigger:
		if (is_ifs)
			continue;

		/* Catch <, > before deciding whether this word is
		 * an assignment. a=1 2>z b=2: b=2 is still assignment */
		switch (ch) {
		case '>':
			redir_fd = redirect_opt_num(&dest);
			if (done_word(&dest, &ctx)) {
				goto parse_error;
			}
			redir_style = REDIRECT_OVERWRITE;
			if (next == '>') {
				redir_style = REDIRECT_APPEND;
				ch = i_getch(input);
				nommu_addchr(&ctx.as_string, ch);
			}
#if 0
			else if (next == '(') {
				syntax_error(">(process) not supported");
				goto parse_error;
			}
#endif
			if (parse_redirect(&ctx, redir_fd, redir_style, input))
				goto parse_error;
			continue; /* back to top of while (1) */
		case '<':
			redir_fd = redirect_opt_num(&dest);
			if (done_word(&dest, &ctx)) {
				goto parse_error;
			}
			redir_style = REDIRECT_INPUT;
			if (next == '<') {
				redir_style = REDIRECT_HEREDOC;
				heredoc_cnt++;
				debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
				ch = i_getch(input);
				nommu_addchr(&ctx.as_string, ch);
			} else if (next == '>') {
				redir_style = REDIRECT_IO;
				ch = i_getch(input);
				nommu_addchr(&ctx.as_string, ch);
			}
#if 0
			else if (next == '(') {
				syntax_error("<(process) not supported");
				goto parse_error;
			}
#endif
			if (parse_redirect(&ctx, redir_fd, redir_style, input))
				goto parse_error;
			continue; /* back to top of while (1) */
		}

		if (dest.o_assignment == MAYBE_ASSIGNMENT
		 /* check that we are not in word in "a=1 2>word b=1": */
		 && !ctx.pending_redirect
		) {
			/* ch is a special char and thus this word
			 * cannot be an assignment */
			dest.o_assignment = NOT_ASSIGNMENT;
		}

		/* Note: nommu_addchr(&ctx.as_string, ch) is already done */

		switch (ch) {
		case '#':
			if (dest.length == 0) {
				while (1) {
					ch = i_peek(input);
					if (ch == EOF || ch == '\n')
						break;
					i_getch(input);
					/* note: we do not add it to &ctx.as_string */
				}
				nommu_addchr(&ctx.as_string, '\n');
			} else {
				o_addQchr(&dest, ch);
			}
			break;
		case '\\':
			if (next == EOF) {
				syntax_error("\\<eof>");
				xfunc_die();
			}
			ch = i_getch(input);
			if (ch != '\n') {
				o_addchr(&dest, '\\');
				/*nommu_addchr(&ctx.as_string, '\\'); - already done */
				o_addchr(&dest, ch);
				nommu_addchr(&ctx.as_string, ch);
				/* Example: echo Hello \2>file
				 * we need to know that word 2 is quoted */
				dest.o_quoted = 1;
			}
#if !BB_MMU
			else {
				/* It's "\<newline>". Remove trailing '\' from ctx.as_string */
				ctx.as_string.data[--ctx.as_string.length] = '\0';
			}
#endif
			break;
		case '$':
			if (parse_dollar(&ctx.as_string, &dest, input) != 0) {
				debug_printf_parse("parse_stream parse error: "
					"parse_dollar returned non-0\n");
				goto parse_error;
			}
			break;
		case '\'':
			dest.o_quoted = 1;
			while (1) {
				ch = i_getch(input);
				if (ch == EOF) {
					syntax_error_unterm_ch('\'');
					/*xfunc_die(); - redundant */
				}
				nommu_addchr(&ctx.as_string, ch);
				if (ch == '\'')
					break;
				o_addqchr(&dest, ch);
			}
			break;
		case '"':
			dest.o_quoted = 1;
			is_in_dquote ^= 1; /* invert */
			if (dest.o_assignment == NOT_ASSIGNMENT)
				dest.o_escape ^= 1;
			break;
#if ENABLE_HUSH_TICK
		case '`': {
			unsigned pos;

			o_addchr(&dest, SPECIAL_VAR_SYMBOL);
			o_addchr(&dest, '`');
			pos = dest.length;
			add_till_backquote(&dest, input);
# if !BB_MMU
			o_addstr(&ctx.as_string, dest.data + pos);
			o_addchr(&ctx.as_string, '`');
# endif
			o_addchr(&dest, SPECIAL_VAR_SYMBOL);
			//debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
			break;
		}
#endif
		case ';':
#if ENABLE_HUSH_CASE
 case_semi:
#endif
			if (done_word(&dest, &ctx)) {
				goto parse_error;
			}
			done_pipe(&ctx, PIPE_SEQ);
#if ENABLE_HUSH_CASE
			/* Eat multiple semicolons, detect
			 * whether it means something special */
			while (1) {
				ch = i_peek(input);
				if (ch != ';')
					break;
				ch = i_getch(input);
				nommu_addchr(&ctx.as_string, ch);
				if (ctx.ctx_res_w == RES_CASE_BODY) {
					ctx.ctx_dsemicolon = 1;
					ctx.ctx_res_w = RES_MATCH;
					break;
				}
			}
#endif
 new_cmd:
			/* We just finished a cmd. New one may start
			 * with an assignment */
			dest.o_assignment = MAYBE_ASSIGNMENT;
			break;
		case '&':
			if (done_word(&dest, &ctx)) {
				goto parse_error;
			}
			if (next == '&') {
				ch = i_getch(input);
				nommu_addchr(&ctx.as_string, ch);
				done_pipe(&ctx, PIPE_AND);
			} else {
				done_pipe(&ctx, PIPE_BG);
			}
			goto new_cmd;
		case '|':
			if (done_word(&dest, &ctx)) {
				goto parse_error;
			}
#if ENABLE_HUSH_CASE
			if (ctx.ctx_res_w == RES_MATCH)
				break; /* we are in case's "word | word)" */
#endif
			if (next == '|') { /* || */
				ch = i_getch(input);
				nommu_addchr(&ctx.as_string, ch);
				done_pipe(&ctx, PIPE_OR);
			} else {
				/* we could pick up a file descriptor choice here
				 * with redirect_opt_num(), but bash doesn't do it.
				 * "echo foo 2| cat" yields "foo 2". */
				done_command(&ctx);
#if !BB_MMU
				o_reset_to_empty_unquoted(&ctx.as_string);
#endif
			}
			goto new_cmd;
		case '(':
#if ENABLE_HUSH_CASE
			/* "case... in [(]word)..." - skip '(' */
			if (ctx.ctx_res_w == RES_MATCH
			 && ctx.command->argv == NULL /* not (word|(... */
			 && dest.length == 0 /* not word(... */
			 && dest.o_quoted == 0 /* not ""(... */
			) {
				continue;
			}
#endif
		case '{':
			if (parse_group(&dest, &ctx, input, ch) != 0) {
				goto parse_error;
			}
			goto new_cmd;
		case ')':
#if ENABLE_HUSH_CASE
			if (ctx.ctx_res_w == RES_MATCH)
				goto case_semi;
#endif
		case '}':
			/* proper use of this character is caught by end_trigger:
			 * if we see {, we call parse_group(..., end_trigger='}')
			 * and it will match } earlier (not here). */
			syntax_error_unexpected_ch(ch);
			goto parse_error;
		default:
			if (HUSH_DEBUG)
				bb_error_msg_and_die("BUG: unexpected %c\n", ch);
		}
	} /* while (1) */

 parse_error:
	{
		struct parse_context *pctx;
		IF_HAS_KEYWORDS(struct parse_context *p2;)

		/* Clean up allocated tree.
		 * Sample for finding leaks on syntax error recovery path.
		 * Run it from interactive shell, watch pmap `pidof hush`.
		 * while if false; then false; fi; do break; fi
		 * Samples to catch leaks at execution:
		 * while if (true | {true;}); then echo ok; fi; do break; done
		 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
		 */
		pctx = &ctx;
		do {
			/* Update pipe/command counts,
			 * otherwise freeing may miss some */
			done_pipe(pctx, PIPE_SEQ);
			debug_printf_clean("freeing list %p from ctx %p\n",
					pctx->list_head, pctx);
			debug_print_tree(pctx->list_head, 0);
			free_pipe_list(pctx->list_head);
			debug_printf_clean("freed list %p\n", pctx->list_head);
#if !BB_MMU
			o_free_unsafe(&pctx->as_string);
#endif
			IF_HAS_KEYWORDS(p2 = pctx->stack;)
			if (pctx != &ctx) {
				free(pctx);
			}
			IF_HAS_KEYWORDS(pctx = p2;)
		} while (HAS_KEYWORDS && pctx);
		/* Free text, clear all dest fields */
		o_free(&dest);
		/* If we are not in top-level parse, we return,
		 * our caller will propagate error.
		 */
		if (end_trigger != ';') {
#if !BB_MMU
			if (pstring)
				*pstring = NULL;
#endif
			debug_leave();
			return ERR_PTR;
		}
		/* Discard cached input, force prompt */
		input->p = NULL;
		IF_HUSH_INTERACTIVE(input->promptme = 1;)
		goto reset;
	}
}

/* Executing from string: eval, sh -c '...'
 *          or from file: /etc/profile, . file, sh <script>, sh (intereactive)
 * end_trigger controls how often we stop parsing
 * NUL: parse all, execute, return
 * ';': parse till ';' or newline, execute, repeat till EOF
 */
static void parse_and_run_stream(struct in_str *inp, int end_trigger)
{
	/* Why we need empty flag?
	 * An obscure corner case "false; ``; echo $?":
	 * empty command in `` should still set $? to 0.
	 * But we can't just set $? to 0 at the start,
	 * this breaks "false; echo `echo $?`" case.
	 */
	bool empty = 1;
	while (1) {
		struct pipe *pipe_list;

		pipe_list = parse_stream(NULL, inp, end_trigger);
		if (!pipe_list) { /* EOF */
			if (empty)
				G.last_exitcode = 0;
			break;
		}
		debug_print_tree(pipe_list, 0);
		debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
		run_and_free_list(pipe_list);
		empty = 0;
	}
}

static void parse_and_run_string(const char *s)
{
	struct in_str input;
	setup_string_in_str(&input, s);
	parse_and_run_stream(&input, '\0');
}

static void parse_and_run_file(FILE *f)
{
	struct in_str input;
	setup_file_in_str(&input, f);
	parse_and_run_stream(&input, ';');
}

/* Called a few times only (or even once if "sh -c") */
static void init_sigmasks(void)
{
	unsigned sig;
	unsigned mask;
	sigset_t old_blocked_set;

	if (!G.inherited_set_is_saved) {
		sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
		G.inherited_set = G.blocked_set;
	}
	old_blocked_set = G.blocked_set;

	mask = (1 << SIGQUIT);
	if (G_interactive_fd) {
		mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
		if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
			mask |= SPECIAL_JOB_SIGS;
	}
	G.non_DFL_mask = mask;

	sig = 0;
	while (mask) {
		if (mask & 1)
			sigaddset(&G.blocked_set, sig);
		mask >>= 1;
		sig++;
	}
	sigdelset(&G.blocked_set, SIGCHLD);

	if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
		sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);

	/* POSIX allows shell to re-enable SIGCHLD
	 * even if it was SIG_IGN on entry */
#if ENABLE_HUSH_FAST
	G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
	if (!G.inherited_set_is_saved)
		signal(SIGCHLD, SIGCHLD_handler);
#else
	if (!G.inherited_set_is_saved)
		signal(SIGCHLD, SIG_DFL);
#endif

	G.inherited_set_is_saved = 1;
}

#if ENABLE_HUSH_JOB
/* helper */
static void maybe_set_to_sigexit(int sig)
{
	void (*handler)(int);
	/* non_DFL_mask'ed signals are, well, masked,
	 * no need to set handler for them.
	 */
	if (!((G.non_DFL_mask >> sig) & 1)) {
		handler = signal(sig, sigexit);
		if (handler == SIG_IGN) /* oops... restore back to IGN! */
			signal(sig, handler);
	}
}
/* Set handlers to restore tty pgrp and exit */
static void set_fatal_handlers(void)
{
	/* We _must_ restore tty pgrp on fatal signals */
	if (HUSH_DEBUG) {
		maybe_set_to_sigexit(SIGILL );
		maybe_set_to_sigexit(SIGFPE );
		maybe_set_to_sigexit(SIGBUS );
		maybe_set_to_sigexit(SIGSEGV);
		maybe_set_to_sigexit(SIGTRAP);
	} /* else: hush is perfect. what SEGV? */
	maybe_set_to_sigexit(SIGABRT);
	/* bash 3.2 seems to handle these just like 'fatal' ones */
	maybe_set_to_sigexit(SIGPIPE);
	maybe_set_to_sigexit(SIGALRM);
	/* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
	 * if we aren't interactive... but in this case
	 * we never want to restore pgrp on exit, and this fn is not called */
	/*maybe_set_to_sigexit(SIGHUP );*/
	/*maybe_set_to_sigexit(SIGTERM);*/
	/*maybe_set_to_sigexit(SIGINT );*/
}
#endif

static int set_mode(const char cstate, const char mode)
{
	int state = (cstate == '-' ? 1 : 0);
	switch (mode) {
		case 'n': G.fake_mode = state; break;
		case 'x': /*G.debug_mode = state;*/ break;
		default:  return EXIT_FAILURE;
	}
	return EXIT_SUCCESS;
}

int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int hush_main(int argc, char **argv)
{
	static const struct variable const_shell_ver = {
		.next = NULL,
		.varstr = (char*)hush_version_str,
		.max_len = 1, /* 0 can provoke free(name) */
		.flg_export = 1,
		.flg_read_only = 1,
	};
	int opt;
	unsigned builtin_argc;
	char **e;
	struct variable *cur_var;

	INIT_G();
	if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
		G.last_exitcode = EXIT_SUCCESS;
#if !BB_MMU
	G.argv0_for_re_execing = argv[0];
#endif
	/* Deal with HUSH_VERSION */
	G.shell_ver = const_shell_ver; /* copying struct here */
	G.top_var = &G.shell_ver;
	debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
	unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
	/* Initialize our shell local variables with the values
	 * currently living in the environment */
	cur_var = G.top_var;
	e = environ;
	if (e) while (*e) {
		char *value = strchr(*e, '=');
		if (value) { /* paranoia */
			cur_var->next = xzalloc(sizeof(*cur_var));
			cur_var = cur_var->next;
			cur_var->varstr = *e;
			cur_var->max_len = strlen(*e);
			cur_var->flg_export = 1;
		}
		e++;
	}
	/* reinstate HUSH_VERSION */
	debug_printf_env("putenv '%s'\n", hush_version_str);
	putenv((char *)hush_version_str);

	/* Export PWD */
	set_pwd_var(/*exp:*/ 1);
	/* bash also exports SHLVL and _,
	 * and sets (but doesn't export) the following variables:
	 * BASH=/bin/bash
	 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
	 * BASH_VERSION='3.2.0(1)-release'
	 * HOSTTYPE=i386
	 * MACHTYPE=i386-pc-linux-gnu
	 * OSTYPE=linux-gnu
	 * HOSTNAME=<xxxxxxxxxx>
	 * PPID=<NNNNN> - we also do it elsewhere
	 * EUID=<NNNNN>
	 * UID=<NNNNN>
	 * GROUPS=()
	 * LINES=<NNN>
	 * COLUMNS=<NNN>
	 * BASH_ARGC=()
	 * BASH_ARGV=()
	 * BASH_LINENO=()
	 * BASH_SOURCE=()
	 * DIRSTACK=()
	 * PIPESTATUS=([0]="0")
	 * HISTFILE=/<xxx>/.bash_history
	 * HISTFILESIZE=500
	 * HISTSIZE=500
	 * MAILCHECK=60
	 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
	 * SHELL=/bin/bash
	 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
	 * TERM=dumb
	 * OPTERR=1
	 * OPTIND=1
	 * IFS=$' \t\n'
	 * PS1='\s-\v\$ '
	 * PS2='> '
	 * PS4='+ '
	 */

#if ENABLE_FEATURE_EDITING
	G.line_input_state = new_line_input_t(FOR_SHELL);
#endif
	G.global_argc = argc;
	G.global_argv = argv;
	/* Initialize some more globals to non-zero values */
	cmdedit_update_prompt();

	if (setjmp(die_jmp)) {
		/* xfunc has failed! die die die */
		/* no EXIT traps, this is an escape hatch! */
		G.exiting = 1;
		hush_exit(xfunc_error_retval);
	}

	/* Shell is non-interactive at first. We need to call
	 * init_sigmasks() if we are going to execute "sh <script>",
	 * "sh -c <cmds>" or login shell's /etc/profile and friends.
	 * If we later decide that we are interactive, we run init_sigmasks()
	 * in order to intercept (more) signals.
	 */

	/* Parse options */
	/* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
	builtin_argc = 0;
	while (1) {
		opt = getopt(argc, argv, "+c:xins"
#if !BB_MMU
				"<:$:R:V:"
# if ENABLE_HUSH_FUNCTIONS
				"F:"
# endif
#endif
		);
		if (opt <= 0)
			break;
		switch (opt) {
		case 'c':
			/* Possibilities:
			 * sh ... -c 'script'
			 * sh ... -c 'script' ARG0 [ARG1...]
			 * On NOMMU, if builtin_argc != 0,
			 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
			 * "" needs to be replaced with NULL
			 * and BARGV vector fed to builtin function.
			 * Note: the form without ARG0 never happens:
			 * sh ... -c 'builtin' BARGV... ""
			 */
			if (!G.root_pid) {
				G.root_pid = getpid();
				G.root_ppid = getppid();
			}
			G.global_argv = argv + optind;
			G.global_argc = argc - optind;
			if (builtin_argc) {
				/* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
				const struct built_in_command *x;

				init_sigmasks();
				x = find_builtin(optarg);
				if (x) { /* paranoia */
					G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
					G.global_argv += builtin_argc;
					G.global_argv[-1] = NULL; /* replace "" */
					G.last_exitcode = x->b_function(argv + optind - 1);
				}
				goto final_return;
			}
			if (!G.global_argv[0]) {
				/* -c 'script' (no params): prevent empty $0 */
				G.global_argv--; /* points to argv[i] of 'script' */
				G.global_argv[0] = argv[0];
				G.global_argc++;
			} /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
			init_sigmasks();
			parse_and_run_string(optarg);
			goto final_return;
		case 'i':
			/* Well, we cannot just declare interactiveness,
			 * we have to have some stuff (ctty, etc) */
			/* G_interactive_fd++; */
			break;
		case 's':
			/* "-s" means "read from stdin", but this is how we always
			 * operate, so simply do nothing here. */
			break;
#if !BB_MMU
		case '<': /* "big heredoc" support */
			full_write1_str(optarg);
			_exit(0);
		case '$': {
			unsigned long long empty_trap_mask;

			G.root_pid = bb_strtou(optarg, &optarg, 16);
			optarg++;
			G.root_ppid = bb_strtou(optarg, &optarg, 16);
			optarg++;
			G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
			optarg++;
			G.last_exitcode = bb_strtou(optarg, &optarg, 16);
			optarg++;
			builtin_argc = bb_strtou(optarg, &optarg, 16);
			optarg++;
			empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
			if (empty_trap_mask != 0) {
				int sig;
				init_sigmasks();
				G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
				for (sig = 1; sig < NSIG; sig++) {
					if (empty_trap_mask & (1LL << sig)) {
						G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
						sigaddset(&G.blocked_set, sig);
					}
				}
				sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
			}
# if ENABLE_HUSH_LOOPS
			optarg++;
			G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
# endif
			break;
		}
		case 'R':
		case 'V':
			set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
			break;
# if ENABLE_HUSH_FUNCTIONS
		case 'F': {
			struct function *funcp = new_function(optarg);
			/* funcp->name is already set to optarg */
			/* funcp->body is set to NULL. It's a special case. */
			funcp->body_as_string = argv[optind];
			optind++;
			break;
		}
# endif
#endif
		case 'n':
		case 'x':
			if (!set_mode('-', opt))
				break;
		default:
#ifndef BB_VER
			fprintf(stderr, "Usage: sh [FILE]...\n"
					"   or: sh -c command [args]...\n\n");
			exit(EXIT_FAILURE);
#else
			bb_show_usage();
#endif
		}
	} /* option parsing loop */

	if (!G.root_pid) {
		G.root_pid = getpid();
		G.root_ppid = getppid();
	}

	/* If we are login shell... */
	if (argv[0] && argv[0][0] == '-') {
		FILE *input;
		debug_printf("sourcing /etc/profile\n");
		input = fopen_for_read("/etc/profile");
		if (input != NULL) {
			close_on_exec_on(fileno(input));
			init_sigmasks();
			parse_and_run_file(input);
			fclose(input);
		}
		/* bash: after sourcing /etc/profile,
		 * tries to source (in the given order):
		 * ~/.bash_profile, ~/.bash_login, ~/.profile,
		 * stopping on first found. --noprofile turns this off.
		 * bash also sources ~/.bash_logout on exit.
		 * If called as sh, skips .bash_XXX files.
		 */
	}

	if (argv[optind]) {
		FILE *input;
		/*
		 * "bash <script>" (which is never interactive (unless -i?))
		 * sources $BASH_ENV here (without scanning $PATH).
		 * If called as sh, does the same but with $ENV.
		 */
		debug_printf("running script '%s'\n", argv[optind]);
		G.global_argv = argv + optind;
		G.global_argc = argc - optind;
		input = xfopen_for_read(argv[optind]);
		close_on_exec_on(fileno(input));
		init_sigmasks();
		parse_and_run_file(input);
#if ENABLE_FEATURE_CLEAN_UP
		fclose(input);
#endif
		goto final_return;
	}

	/* Up to here, shell was non-interactive. Now it may become one.
	 * NB: don't forget to (re)run init_sigmasks() as needed.
	 */

	/* A shell is interactive if the '-i' flag was given,
	 * or if all of the following conditions are met:
	 *    no -c command
	 *    no arguments remaining or the -s flag given
	 *    standard input is a terminal
	 *    standard output is a terminal
	 * Refer to Posix.2, the description of the 'sh' utility.
	 */
#if ENABLE_HUSH_JOB
	if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
		G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
		debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
		if (G_saved_tty_pgrp < 0)
			G_saved_tty_pgrp = 0;

		/* try to dup stdin to high fd#, >= 255 */
		G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
		if (G_interactive_fd < 0) {
			/* try to dup to any fd */
			G_interactive_fd = dup(STDIN_FILENO);
			if (G_interactive_fd < 0) {
				/* give up */
				G_interactive_fd = 0;
				G_saved_tty_pgrp = 0;
			}
		}
// TODO: track & disallow any attempts of user
// to (inadvertently) close/redirect G_interactive_fd
	}
	debug_printf("interactive_fd:%d\n", G_interactive_fd);
	if (G_interactive_fd) {
		close_on_exec_on(G_interactive_fd);

		if (G_saved_tty_pgrp) {
			/* If we were run as 'hush &', sleep until we are
			 * in the foreground (tty pgrp == our pgrp).
			 * If we get started under a job aware app (like bash),
			 * make sure we are now in charge so we don't fight over
			 * who gets the foreground */
			while (1) {
				pid_t shell_pgrp = getpgrp();
				G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
				if (G_saved_tty_pgrp == shell_pgrp)
					break;
				/* send TTIN to ourself (should stop us) */
				kill(- shell_pgrp, SIGTTIN);
			}
		}

		/* Block some signals */
		init_sigmasks();

		if (G_saved_tty_pgrp) {
			/* Set other signals to restore saved_tty_pgrp */
			set_fatal_handlers();
			/* Put ourselves in our own process group
			 * (bash, too, does this only if ctty is available) */
			bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
			/* Grab control of the terminal */
			tcsetpgrp(G_interactive_fd, getpid());
		}
		/* -1 is special - makes xfuncs longjmp, not exit
		 * (we reset die_sleep = 0 whereever we [v]fork) */
		enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
	} else {
		init_sigmasks();
	}
#elif ENABLE_HUSH_INTERACTIVE
	/* No job control compiled in, only prompt/line editing */
	if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
		G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
		if (G_interactive_fd < 0) {
			/* try to dup to any fd */
			G_interactive_fd = dup(STDIN_FILENO);
			if (G_interactive_fd < 0)
				/* give up */
				G_interactive_fd = 0;
		}
	}
	if (G_interactive_fd) {
		close_on_exec_on(G_interactive_fd);
	}
	init_sigmasks();
#else
	/* We have interactiveness code disabled */
	init_sigmasks();
#endif
	/* bash:
	 * if interactive but not a login shell, sources ~/.bashrc
	 * (--norc turns this off, --rcfile <file> overrides)
	 */

	if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
		/* note: ash and hush share this string */
		printf("\n\n%s %s\n"
			IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
			"\n",
			bb_banner,
			"hush - the humble shell"
		);
	}

	parse_and_run_file(stdin);

 final_return:
#if ENABLE_FEATURE_CLEAN_UP
	if (G.cwd != bb_msg_unknown)
		free((char*)G.cwd);
	cur_var = G.top_var->next;
	while (cur_var) {
		struct variable *tmp = cur_var;
		if (!cur_var->max_len)
			free(cur_var->varstr);
		cur_var = cur_var->next;
		free(tmp);
	}
#endif
	hush_exit(G.last_exitcode);
}


#if ENABLE_LASH
int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int lash_main(int argc, char **argv)
{
	bb_error_msg("lash is deprecated, please use hush instead");
	return hush_main(argc, argv);
}
#endif

#if ENABLE_MSH
int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int msh_main(int argc, char **argv)
{
	//bb_error_msg("msh is deprecated, please use hush instead");
	return hush_main(argc, argv);
}
#endif


/*
 * Built-ins
 */
static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
{
	return 0;
}

static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
{
	int argc = 0;
	while (*argv) {
		argc++;
		argv++;
	}
	return applet_main_func(argc, argv - argc);
}

static int FAST_FUNC builtin_test(char **argv)
{
	return run_applet_main(argv, test_main);
}

static int FAST_FUNC builtin_echo(char **argv)
{
	return run_applet_main(argv, echo_main);
}

#if ENABLE_PRINTF
static int FAST_FUNC builtin_printf(char **argv)
{
	return run_applet_main(argv, printf_main);
}
#endif

static char **skip_dash_dash(char **argv)
{
	argv++;
	if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
		argv++;
	return argv;
}

static int FAST_FUNC builtin_eval(char **argv)
{
	int rcode = EXIT_SUCCESS;

	argv = skip_dash_dash(argv);
	if (*argv) {
		char *str = expand_strvec_to_string(argv);
		/* bash:
		 * eval "echo Hi; done" ("done" is syntax error):
		 * "echo Hi" will not execute too.
		 */
		parse_and_run_string(str);
		free(str);
		rcode = G.last_exitcode;
	}
	return rcode;
}

static int FAST_FUNC builtin_cd(char **argv)
{
	const char *newdir;

	argv = skip_dash_dash(argv);
	newdir = argv[0];
	if (newdir == NULL) {
		/* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
		 * bash says "bash: cd: HOME not set" and does nothing
		 * (exitcode 1)
		 */
		const char *home = get_local_var_value("HOME");
		newdir = home ? home : "/";
	}
	if (chdir(newdir)) {
		/* Mimic bash message exactly */
		bb_perror_msg("cd: %s", newdir);
		return EXIT_FAILURE;
	}
	/* Read current dir (get_cwd(1) is inside) and set PWD.
	 * Note: do not enforce exporting. If PWD was unset or unexported,
	 * set it again, but do not export. bash does the same.
	 */
	set_pwd_var(/*exp:*/ 0);
	return EXIT_SUCCESS;
}

static int FAST_FUNC builtin_exec(char **argv)
{
	argv = skip_dash_dash(argv);
	if (argv[0] == NULL)
		return EXIT_SUCCESS; /* bash does this */

	/* Careful: we can end up here after [v]fork. Do not restore
	 * tty pgrp then, only top-level shell process does that */
	if (G_saved_tty_pgrp && getpid() == G.root_pid)
		tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);

	/* TODO: if exec fails, bash does NOT exit! We do.
	 * We'll need to undo sigprocmask (it's inside execvp_or_die)
	 * and tcsetpgrp, and this is inherently racy.
	 */
	execvp_or_die(argv);
}

static int FAST_FUNC builtin_exit(char **argv)
{
	debug_printf_exec("%s()\n", __func__);

	/* interactive bash:
	 * # trap "echo EEE" EXIT
	 * # exit
	 * exit
	 * There are stopped jobs.
	 * (if there are _stopped_ jobs, running ones don't count)
	 * # exit
	 * exit
	 # EEE (then bash exits)
	 *
	 * we can use G.exiting = -1 as indicator "last cmd was exit"
	 */

	/* note: EXIT trap is run by hush_exit */
	argv = skip_dash_dash(argv);
	if (argv[0] == NULL)
		hush_exit(G.last_exitcode);
	/* mimic bash: exit 123abc == exit 255 + error msg */
	xfunc_error_retval = 255;
	/* bash: exit -2 == exit 254, no error msg */
	hush_exit(xatoi(argv[0]) & 0xff);
}

static void print_escaped(const char *s)
{
	if (*s == '\'')
		goto squote;
	do {
		const char *p = strchrnul(s, '\'');
		/* print 'xxxx', possibly just '' */
		printf("'%.*s'", (int)(p - s), s);
		if (*p == '\0')
			break;
		s = p;
 squote:
		/* s points to '; print "'''...'''" */
		putchar('"');
		do putchar('\''); while (*++s == '\'');
		putchar('"');
	} while (*s);
}

#if !ENABLE_HUSH_LOCAL
#define helper_export_local(argv, exp, lvl) \
	helper_export_local(argv, exp)
#endif
static void helper_export_local(char **argv, int exp, int lvl)
{
	do {
		char *name = *argv;

		/* So far we do not check that name is valid (TODO?) */

		if (strchr(name, '=') == NULL) {
			struct variable *var;

			var = get_local_var(name);
			if (exp == -1) { /* unexporting? */
				/* export -n NAME (without =VALUE) */
				if (var) {
					var->flg_export = 0;
					debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
					unsetenv(name);
				} /* else: export -n NOT_EXISTING_VAR: no-op */
				continue;
			}
			if (exp == 1) { /* exporting? */
				/* export NAME (without =VALUE) */
				if (var) {
					var->flg_export = 1;
					debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
					putenv(var->varstr);
					continue;
				}
			}
			/* Exporting non-existing variable.
			 * bash does not put it in environment,
			 * but remembers that it is exported,
			 * and does put it in env when it is set later.
			 * We just set it to "" and export. */
			/* Or, it's "local NAME" (without =VALUE).
			 * bash sets the value to "". */
			name = xasprintf("%s=", name);
		} else {
			/* (Un)exporting/making local NAME=VALUE */
			name = xstrdup(name);
		}
		set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
	} while (*++argv);
}

static int FAST_FUNC builtin_export(char **argv)
{
	unsigned opt_unexport;

#if ENABLE_HUSH_EXPORT_N
	/* "!": do not abort on errors */
	opt_unexport = getopt32(argv, "!n");
	if (opt_unexport == (uint32_t)-1)
		return EXIT_FAILURE;
	argv += optind;
#else
	opt_unexport = 0;
	argv++;
#endif

	if (argv[0] == NULL) {
		char **e = environ;
		if (e) {
			while (*e) {
#if 0
				puts(*e++);
#else
				/* ash emits: export VAR='VAL'
				 * bash: declare -x VAR="VAL"
				 * we follow ash example */
				const char *s = *e++;
				const char *p = strchr(s, '=');

				if (!p) /* wtf? take next variable */
					continue;
				/* export var= */
				printf("export %.*s", (int)(p - s) + 1, s);
				print_escaped(p + 1);
				putchar('\n');
#endif
			}
			/*fflush_all(); - done after each builtin anyway */
		}
		return EXIT_SUCCESS;
	}

	helper_export_local(argv, (opt_unexport ? -1 : 1), 0);

	return EXIT_SUCCESS;
}

#if ENABLE_HUSH_LOCAL
static int FAST_FUNC builtin_local(char **argv)
{
	if (G.func_nest_level == 0) {
		bb_error_msg("%s: not in a function", argv[0]);
		return EXIT_FAILURE; /* bash compat */
	}
	helper_export_local(argv, 0, G.func_nest_level);
	return EXIT_SUCCESS;
}
#endif

static int FAST_FUNC builtin_trap(char **argv)
{
	int sig;
	char *new_cmd;

	if (!G.traps)
		G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);

	argv++;
	if (!*argv) {
		int i;
		/* No args: print all trapped */
		for (i = 0; i < NSIG; ++i) {
			if (G.traps[i]) {
				printf("trap -- ");
				print_escaped(G.traps[i]);
				/* note: bash adds "SIG", but only if invoked
				 * as "bash". If called as "sh", or if set -o posix,
				 * then it prints short signal names.
				 * We are printing short names: */
				printf(" %s\n", get_signame(i));
			}
		}
		/*fflush_all(); - done after each builtin anyway */
		return EXIT_SUCCESS;
	}

	new_cmd = NULL;
	/* If first arg is a number: reset all specified signals */
	sig = bb_strtou(*argv, NULL, 10);
	if (errno == 0) {
		int ret;
 process_sig_list:
		ret = EXIT_SUCCESS;
		while (*argv) {
			sig = get_signum(*argv++);
			if (sig < 0 || sig >= NSIG) {
				ret = EXIT_FAILURE;
				/* Mimic bash message exactly */
				bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
				continue;
			}

			free(G.traps[sig]);
			G.traps[sig] = xstrdup(new_cmd);

			debug_printf("trap: setting SIG%s (%i) to '%s'\n",
				get_signame(sig), sig, G.traps[sig]);

			/* There is no signal for 0 (EXIT) */
			if (sig == 0)
				continue;

			if (new_cmd) {
				sigaddset(&G.blocked_set, sig);
			} else {
				/* There was a trap handler, we are removing it
				 * (if sig has non-DFL handling,
				 * we don't need to do anything) */
				if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
					continue;
				sigdelset(&G.blocked_set, sig);
			}
		}
		sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
		return ret;
	}

	if (!argv[1]) { /* no second arg */
		bb_error_msg("trap: invalid arguments");
		return EXIT_FAILURE;
	}

	/* First arg is "-": reset all specified to default */
	/* First arg is "--": skip it, the rest is "handler SIGs..." */
	/* Everything else: set arg as signal handler
	 * (includes "" case, which ignores signal) */
	if (argv[0][0] == '-') {
		if (argv[0][1] == '\0') { /* "-" */
			/* new_cmd remains NULL: "reset these sigs" */
			goto reset_traps;
		}
		if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
			argv++;
		}
		/* else: "-something", no special meaning */
	}
	new_cmd = *argv;
 reset_traps:
	argv++;
	goto process_sig_list;
}

/* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
static int FAST_FUNC builtin_type(char **argv)
{
	int ret = EXIT_SUCCESS;

	while (*++argv) {
		const char *type;
		char *path = NULL;

		if (0) {} /* make conditional compile easier below */
		/*else if (find_alias(*argv))
			type = "an alias";*/
#if ENABLE_HUSH_FUNCTIONS
		else if (find_function(*argv))
			type = "a function";
#endif
		else if (find_builtin(*argv))
			type = "a shell builtin";
		else if ((path = find_in_path(*argv)) != NULL)
			type = path;
		else {
			bb_error_msg("type: %s: not found", *argv);
			ret = EXIT_FAILURE;
			continue;
		}

		printf("%s is %s\n", *argv, type);
		free(path);
	}

	return ret;
}

#if ENABLE_HUSH_JOB
/* built-in 'fg' and 'bg' handler */
static int FAST_FUNC builtin_fg_bg(char **argv)
{
	int i, jobnum;
	struct pipe *pi;

	if (!G_interactive_fd)
		return EXIT_FAILURE;

	/* If they gave us no args, assume they want the last backgrounded task */
	if (!argv[1]) {
		for (pi = G.job_list; pi; pi = pi->next) {
			if (pi->jobid == G.last_jobid) {
				goto found;
			}
		}
		bb_error_msg("%s: no current job", argv[0]);
		return EXIT_FAILURE;
	}
	if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
		bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
		return EXIT_FAILURE;
	}
	for (pi = G.job_list; pi; pi = pi->next) {
		if (pi->jobid == jobnum) {
			goto found;
		}
	}
	bb_error_msg("%s: %d: no such job", argv[0], jobnum);
	return EXIT_FAILURE;
 found:
	/* TODO: bash prints a string representation
	 * of job being foregrounded (like "sleep 1 | cat") */
	if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
		/* Put the job into the foreground.  */
		tcsetpgrp(G_interactive_fd, pi->pgrp);
	}

	/* Restart the processes in the job */
	debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
	for (i = 0; i < pi->num_cmds; i++) {
		debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
		pi->cmds[i].is_stopped = 0;
	}
	pi->stopped_cmds = 0;

	i = kill(- pi->pgrp, SIGCONT);
	if (i < 0) {
		if (errno == ESRCH) {
			delete_finished_bg_job(pi);
			return EXIT_SUCCESS;
		}
		bb_perror_msg("kill (SIGCONT)");
	}

	if (argv[0][0] == 'f') {
		remove_bg_job(pi);
		return checkjobs_and_fg_shell(pi);
	}
	return EXIT_SUCCESS;
}
#endif

#if ENABLE_HUSH_HELP
static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
{
	const struct built_in_command *x;

	printf(
		"Built-in commands:\n"
		"------------------\n");
	for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
		if (x->b_descr)
			printf("%-10s%s\n", x->b_cmd, x->b_descr);
	}
	bb_putchar('\n');
	return EXIT_SUCCESS;
}
#endif

#if ENABLE_HUSH_JOB
static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
{
	struct pipe *job;
	const char *status_string;

	for (job = G.job_list; job; job = job->next) {
		if (job->alive_cmds == job->stopped_cmds)
			status_string = "Stopped";
		else
			status_string = "Running";

		printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
	}
	return EXIT_SUCCESS;
}
#endif

#if HUSH_DEBUG
static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
{
	void *p;
	unsigned long l;

# ifdef M_TRIM_THRESHOLD
	/* Optional. Reduces probability of false positives */
	malloc_trim(0);
# endif
	/* Crude attempt to find where "free memory" starts,
	 * sans fragmentation. */
	p = malloc(240);
	l = (unsigned long)p;
	free(p);
	p = malloc(3400);
	if (l < (unsigned long)p) l = (unsigned long)p;
	free(p);

	if (!G.memleak_value)
		G.memleak_value = l;

	l -= G.memleak_value;
	if ((long)l < 0)
		l = 0;
	l /= 1024;
	if (l > 127)
		l = 127;

	/* Exitcode is "how many kilobytes we leaked since 1st call" */
	return l;
}
#endif

static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
{
	puts(get_cwd(0));
	return EXIT_SUCCESS;
}

static int FAST_FUNC builtin_read(char **argv)
{
	const char *r;
	char *opt_n = NULL;
	char *opt_p = NULL;
	char *opt_t = NULL;
	char *opt_u = NULL;
	int read_flags;

	/* "!": do not abort on errors.
	 * Option string must start with "sr" to match BUILTIN_READ_xxx
	 */
	read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
	if (read_flags == (uint32_t)-1)
		return EXIT_FAILURE;
	argv += optind;

	r = shell_builtin_read(set_local_var_from_halves,
		argv,
		get_local_var_value("IFS"), /* can be NULL */
		read_flags,
		opt_n,
		opt_p,
		opt_t,
		opt_u
	);

	if ((uintptr_t)r > 1) {
		bb_error_msg("%s", r);
		r = (char*)(uintptr_t)1;
	}

	return (uintptr_t)r;
}

/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
 * built-in 'set' handler
 * SUSv3 says:
 * set [-abCefhmnuvx] [-o option] [argument...]
 * set [+abCefhmnuvx] [+o option] [argument...]
 * set -- [argument...]
 * set -o
 * set +o
 * Implementations shall support the options in both their hyphen and
 * plus-sign forms. These options can also be specified as options to sh.
 * Examples:
 * Write out all variables and their values: set
 * Set $1, $2, and $3 and set "$#" to 3: set c a b
 * Turn on the -x and -v options: set -xv
 * Unset all positional parameters: set --
 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
 * Set the positional parameters to the expansion of x, even if x expands
 * with a leading '-' or '+': set -- $x
 *
 * So far, we only support "set -- [argument...]" and some of the short names.
 */
static int FAST_FUNC builtin_set(char **argv)
{
	int n;
	char **pp, **g_argv;
	char *arg = *++argv;

	if (arg == NULL) {
		struct variable *e;
		for (e = G.top_var; e; e = e->next)
			puts(e->varstr);
		return EXIT_SUCCESS;
	}

	do {
		if (!strcmp(arg, "--")) {
			++argv;
			goto set_argv;
		}
		if (arg[0] != '+' && arg[0] != '-')
			break;
		for (n = 1; arg[n]; ++n)
			if (set_mode(arg[0], arg[n]))
				goto error;
	} while ((arg = *++argv) != NULL);
	/* Now argv[0] is 1st argument */

	if (arg == NULL)
		return EXIT_SUCCESS;
 set_argv:

	/* NB: G.global_argv[0] ($0) is never freed/changed */
	g_argv = G.global_argv;
	if (G.global_args_malloced) {
		pp = g_argv;
		while (*++pp)
			free(*pp);
		g_argv[1] = NULL;
	} else {
		G.global_args_malloced = 1;
		pp = xzalloc(sizeof(pp[0]) * 2);
		pp[0] = g_argv[0]; /* retain $0 */
		g_argv = pp;
	}
	/* This realloc's G.global_argv */
	G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);

	n = 1;
	while (*++pp)
		n++;
	G.global_argc = n;

	return EXIT_SUCCESS;

	/* Nothing known, so abort */
 error:
	bb_error_msg("set: %s: invalid option", arg);
	return EXIT_FAILURE;
}

static int FAST_FUNC builtin_shift(char **argv)
{
	int n = 1;
	argv = skip_dash_dash(argv);
	if (argv[0]) {
		n = atoi(argv[0]);
	}
	if (n >= 0 && n < G.global_argc) {
		if (G.global_args_malloced) {
			int m = 1;
			while (m <= n)
				free(G.global_argv[m++]);
		}
		G.global_argc -= n;
		memmove(&G.global_argv[1], &G.global_argv[n+1],
				G.global_argc * sizeof(G.global_argv[0]));
		return EXIT_SUCCESS;
	}
	return EXIT_FAILURE;
}

static int FAST_FUNC builtin_source(char **argv)
{
	char *arg_path, *filename;
	FILE *input;
	save_arg_t sv;
#if ENABLE_HUSH_FUNCTIONS
	smallint sv_flg;
#endif

	argv = skip_dash_dash(argv);
	filename = argv[0];
	if (!filename) {
		/* bash says: "bash: .: filename argument required" */
		return 2; /* bash compat */
	}
	arg_path = NULL;
	if (!strchr(filename, '/')) {
		arg_path = find_in_path(filename);
		if (arg_path)
			filename = arg_path;
	}
	input = fopen_or_warn(filename, "r");
	free(arg_path);
	if (!input) {
		/* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
		return EXIT_FAILURE;
	}
	close_on_exec_on(fileno(input));

#if ENABLE_HUSH_FUNCTIONS
	sv_flg = G.flag_return_in_progress;
	/* "we are inside sourced file, ok to use return" */
	G.flag_return_in_progress = -1;
#endif
	save_and_replace_G_args(&sv, argv);

	parse_and_run_file(input);
	fclose(input);

	restore_G_args(&sv, argv);
#if ENABLE_HUSH_FUNCTIONS
	G.flag_return_in_progress = sv_flg;
#endif

	return G.last_exitcode;
}

static int FAST_FUNC builtin_umask(char **argv)
{
	int rc;
	mode_t mask;

	mask = umask(0);
	argv = skip_dash_dash(argv);
	if (argv[0]) {
		mode_t old_mask = mask;

		mask ^= 0777;
		rc = bb_parse_mode(argv[0], &mask);
		mask ^= 0777;
		if (rc == 0) {
			mask = old_mask;
			/* bash messages:
			 * bash: umask: 'q': invalid symbolic mode operator
			 * bash: umask: 999: octal number out of range
			 */
			bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
		}
	} else {
		rc = 1;
		/* Mimic bash */
		printf("%04o\n", (unsigned) mask);
		/* fall through and restore mask which we set to 0 */
	}
	umask(mask);

	return !rc; /* rc != 0 - success */
}

/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
static int FAST_FUNC builtin_unset(char **argv)
{
	int ret;
	unsigned opts;

	/* "!": do not abort on errors */
	/* "+": stop at 1st non-option */
	opts = getopt32(argv, "!+vf");
	if (opts == (unsigned)-1)
		return EXIT_FAILURE;
	if (opts == 3) {
		bb_error_msg("unset: -v and -f are exclusive");
		return EXIT_FAILURE;
	}
	argv += optind;

	ret = EXIT_SUCCESS;
	while (*argv) {
		if (!(opts & 2)) { /* not -f */
			if (unset_local_var(*argv)) {
				/* unset <nonexistent_var> doesn't fail.
				 * Error is when one tries to unset RO var.
				 * Message was printed by unset_local_var. */
				ret = EXIT_FAILURE;
			}
		}
#if ENABLE_HUSH_FUNCTIONS
		else {
			unset_func(*argv);
		}
#endif
		argv++;
	}
	return ret;
}

/* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
static int FAST_FUNC builtin_wait(char **argv)
{
	int ret = EXIT_SUCCESS;
	int status, sig;

	argv = skip_dash_dash(argv);
	if (argv[0] == NULL) {
		/* Don't care about wait results */
		/* Note 1: must wait until there are no more children */
		/* Note 2: must be interruptible */
		/* Examples:
		 * $ sleep 3 & sleep 6 & wait
		 * [1] 30934 sleep 3
		 * [2] 30935 sleep 6
		 * [1] Done                   sleep 3
		 * [2] Done                   sleep 6
		 * $ sleep 3 & sleep 6 & wait
		 * [1] 30936 sleep 3
		 * [2] 30937 sleep 6
		 * [1] Done                   sleep 3
		 * ^C <-- after ~4 sec from keyboard
		 * $
		 */
		sigaddset(&G.blocked_set, SIGCHLD);
		sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
		while (1) {
			checkjobs(NULL);
			if (errno == ECHILD)
				break;
			/* Wait for SIGCHLD or any other signal of interest */
			/* sigtimedwait with infinite timeout: */
			sig = sigwaitinfo(&G.blocked_set, NULL);
			if (sig > 0) {
				sig = check_and_run_traps(sig);
				if (sig && sig != SIGCHLD) { /* see note 2 */
					ret = 128 + sig;
					break;
				}
			}
		}
		sigdelset(&G.blocked_set, SIGCHLD);
		sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
		return ret;
	}

	/* This is probably buggy wrt interruptible-ness */
	while (*argv) {
		pid_t pid = bb_strtou(*argv, NULL, 10);
		if (errno) {
			/* mimic bash message */
			bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
			return EXIT_FAILURE;
		}
		if (waitpid(pid, &status, 0) == pid) {
			if (WIFSIGNALED(status))
				ret = 128 + WTERMSIG(status);
			else if (WIFEXITED(status))
				ret = WEXITSTATUS(status);
			else /* wtf? */
				ret = EXIT_FAILURE;
		} else {
			bb_perror_msg("wait %s", *argv);
			ret = 127;
		}
		argv++;
	}

	return ret;
}

#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
{
	if (argv[1]) {
		def = bb_strtou(argv[1], NULL, 10);
		if (errno || def < def_min || argv[2]) {
			bb_error_msg("%s: bad arguments", argv[0]);
			def = UINT_MAX;
		}
	}
	return def;
}
#endif

#if ENABLE_HUSH_LOOPS
static int FAST_FUNC builtin_break(char **argv)
{
	unsigned depth;
	if (G.depth_of_loop == 0) {
		bb_error_msg("%s: only meaningful in a loop", argv[0]);
		return EXIT_SUCCESS; /* bash compat */
	}
	G.flag_break_continue++; /* BC_BREAK = 1 */

	G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
	if (depth == UINT_MAX)
		G.flag_break_continue = BC_BREAK;
	if (G.depth_of_loop < depth)
		G.depth_break_continue = G.depth_of_loop;

	return EXIT_SUCCESS;
}

static int FAST_FUNC builtin_continue(char **argv)
{
	G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
	return builtin_break(argv);
}
#endif

#if ENABLE_HUSH_FUNCTIONS
static int FAST_FUNC builtin_return(char **argv)
{
	int rc;

	if (G.flag_return_in_progress != -1) {
		bb_error_msg("%s: not in a function or sourced script", argv[0]);
		return EXIT_FAILURE; /* bash compat */
	}

	G.flag_return_in_progress = 1;

	/* bash:
	 * out of range: wraps around at 256, does not error out
	 * non-numeric param:
	 * f() { false; return qwe; }; f; echo $?
	 * bash: return: qwe: numeric argument required  <== we do this
	 * 255  <== we also do this
	 */
	rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
	return rc;
}
#endif