aboutsummaryrefslogtreecommitdiff
path: root/coreutils/test.c
blob: 36da4db0b76ad8c98d43163a856bb1fedb43f1b9 (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
/* vi: set sw=4 ts=4: */
/*
 * test implementation for busybox
 *
 * Copyright (c) by a whole pile of folks: 
 *
 * 	test(1); version 7-like  --  author Erik Baalbergen
 * 	modified by Eric Gisin to be used as built-in.
 * 	modified by Arnold Robbins to add SVR3 compatibility
 * 	(-x -c -b -p -u -g -k) plus Korn's -L -nt -ot -ef and new -S (socket).
 * 	modified by J.T. Conklin for NetBSD.
 * 	modified by Herbert Xu to be used as built-in in ash.
 * 	modified by Erik Andersen <andersee@debian.org> to be used 
 * 	in busybox.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Original copyright notice states:
 * 	"This program is in the Public Domain."
 */

#include "internal.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#define BB_DECLARE_EXTERN
#define bb_need_help
#include "messages.c"

/* test(1) accepts the following grammar:
	oexpr	::= aexpr | aexpr "-o" oexpr ;
	aexpr	::= nexpr | nexpr "-a" aexpr ;
	nexpr	::= primary | "!" primary
	primary	::= unary-operator operand
		| operand binary-operator operand
		| operand
		| "(" oexpr ")"
		;
	unary-operator ::= "-r"|"-w"|"-x"|"-f"|"-d"|"-c"|"-b"|"-p"|
		"-u"|"-g"|"-k"|"-s"|"-t"|"-z"|"-n"|"-o"|"-O"|"-G"|"-L"|"-S";

	binary-operator ::= "="|"!="|"-eq"|"-ne"|"-ge"|"-gt"|"-le"|"-lt"|
			"-nt"|"-ot"|"-ef";
	operand ::= <any legal UNIX file name>
*/

enum token {
	EOI,
	FILRD,
	FILWR,
	FILEX,
	FILEXIST,
	FILREG,
	FILDIR,
	FILCDEV,
	FILBDEV,
	FILFIFO,
	FILSOCK,
	FILSYM,
	FILGZ,
	FILTT,
	FILSUID,
	FILSGID,
	FILSTCK,
	FILNT,
	FILOT,
	FILEQ,
	FILUID,
	FILGID,
	STREZ,
	STRNZ,
	STREQ,
	STRNE,
	STRLT,
	STRGT,
	INTEQ,
	INTNE,
	INTGE,
	INTGT,
	INTLE,
	INTLT,
	UNOT,
	BAND,
	BOR,
	LPAREN,
	RPAREN,
	OPERAND
};

enum token_types {
	UNOP,
	BINOP,
	BUNOP,
	BBINOP,
	PAREN
};

struct t_op {
	const char *op_text;
	short op_num, op_type;
} const ops [] = {
	{"-r",	FILRD,	UNOP},
	{"-w",	FILWR,	UNOP},
	{"-x",	FILEX,	UNOP},
	{"-e",	FILEXIST,UNOP},
	{"-f",	FILREG,	UNOP},
	{"-d",	FILDIR,	UNOP},
	{"-c",	FILCDEV,UNOP},
	{"-b",	FILBDEV,UNOP},
	{"-p",	FILFIFO,UNOP},
	{"-u",	FILSUID,UNOP},
	{"-g",	FILSGID,UNOP},
	{"-k",	FILSTCK,UNOP},
	{"-s",	FILGZ,	UNOP},
	{"-t",	FILTT,	UNOP},
	{"-z",	STREZ,	UNOP},
	{"-n",	STRNZ,	UNOP},
	{"-h",	FILSYM,	UNOP},		/* for backwards compat */
	{"-O",	FILUID,	UNOP},
	{"-G",	FILGID,	UNOP},
	{"-L",	FILSYM,	UNOP},
	{"-S",	FILSOCK,UNOP},
	{"=",	STREQ,	BINOP},
	{"!=",	STRNE,	BINOP},
	{"<",	STRLT,	BINOP},
	{">",	STRGT,	BINOP},
	{"-eq",	INTEQ,	BINOP},
	{"-ne",	INTNE,	BINOP},
	{"-ge",	INTGE,	BINOP},
	{"-gt",	INTGT,	BINOP},
	{"-le",	INTLE,	BINOP},
	{"-lt",	INTLT,	BINOP},
	{"-nt",	FILNT,	BINOP},
	{"-ot",	FILOT,	BINOP},
	{"-ef",	FILEQ,	BINOP},
	{"!",	UNOT,	BUNOP},
	{"-a",	BAND,	BBINOP},
	{"-o",	BOR,	BBINOP},
	{"(",	LPAREN,	PAREN},
	{")",	RPAREN,	PAREN},
	{0,	0,	0}
};

char **t_wp;
struct t_op const *t_wp_op;
static gid_t *group_array = NULL;
static int ngroups;

static enum token t_lex();
static int oexpr();
static int aexpr();
static int nexpr();
static int binop();
static int primary();
static int filstat();
static int getn();
static int newerf();
static int olderf();
static int equalf();
static void syntax();
static int test_eaccess();
static int is_a_group_member();
static void initialize_group_array();

extern int
test_main(int argc, char** argv)
{
	int	res;

	if (strcmp(argv[0], "[") == 0) {
		if (strcmp(argv[--argc], "]"))
			fatalError("missing ]\n");
		argv[argc] = NULL;
	}
	if (strcmp(argv[1], dash_dash_help) == 0) {
		usage("test EXPRESSION\n"
			  "or   [ EXPRESSION ]\n"
#ifndef BB_FEATURE_TRIVIAL_HELP
				"\nChecks file types and compares values returning an exit\n"
				"code determined by the value of EXPRESSION.\n"
#endif
				);
	}

	/* Implement special cases from POSIX.2, section 4.62.4 */
	switch (argc) {
	case 1:
		exit( 1);
	case 2:
		exit (*argv[1] == '\0');
	case 3:
		if (argv[1][0] == '!' && argv[1][1] == '\0') {
			exit (!(*argv[2] == '\0'));
		}
		break;
	case 4:
		if (argv[1][0] != '!' || argv[1][1] != '\0') {
			if (t_lex(argv[2]), 
			    t_wp_op && t_wp_op->op_type == BINOP) {
				t_wp = &argv[1];
				exit (binop() == 0);
			}
		}
		break;
	case 5:
		if (argv[1][0] == '!' && argv[1][1] == '\0') {
			if (t_lex(argv[3]), 
			    t_wp_op && t_wp_op->op_type == BINOP) {
				t_wp = &argv[2];
				exit (!(binop() == 0));
			}
		}
		break;
	}

	t_wp = &argv[1];
	res = !oexpr(t_lex(*t_wp));

	if (*t_wp != NULL && *++t_wp != NULL)
		syntax(*t_wp, "unknown operand");

	return( res);
}

static void
syntax(op, msg)
	char	*op;
	char	*msg;
{
	if (op && *op)
		fatalError("%s: %s\n", op, msg);
	else
		fatalError("%s\n", msg);
}

static int
oexpr(n)
	enum token n;
{
	int res;

	res = aexpr(n);
	if (t_lex(*++t_wp) == BOR)
		return oexpr(t_lex(*++t_wp)) || res;
	t_wp--;
	return res;
}

static int
aexpr(n)
	enum token n;
{
	int res;

	res = nexpr(n);
	if (t_lex(*++t_wp) == BAND)
		return aexpr(t_lex(*++t_wp)) && res;
	t_wp--;
	return res;
}

static int
nexpr(n)
	enum token n;			/* token */
{
	if (n == UNOT)
		return !nexpr(t_lex(*++t_wp));
	return primary(n);
}

static int
primary(n)
	enum token n;
{
	int res;

	if (n == EOI)
		syntax(NULL, "argument expected");
	if (n == LPAREN) {
		res = oexpr(t_lex(*++t_wp));
		if (t_lex(*++t_wp) != RPAREN)
			syntax(NULL, "closing paren expected");
		return res;
	}
	if (t_wp_op && t_wp_op->op_type == UNOP) {
		/* unary expression */
		if (*++t_wp == NULL)
			syntax(t_wp_op->op_text, "argument expected");
		switch (n) {
		case STREZ:
			return strlen(*t_wp) == 0;
		case STRNZ:
			return strlen(*t_wp) != 0;
		case FILTT:
			return isatty(getn(*t_wp));
		default:
			return filstat(*t_wp, n);
		}
	}

	if (t_lex(t_wp[1]), t_wp_op && t_wp_op->op_type == BINOP) {
		return binop();
	}	  

	return strlen(*t_wp) > 0;
}

static int
binop()
{
	const char *opnd1, *opnd2;
	struct t_op const *op;

	opnd1 = *t_wp;
	(void) t_lex(*++t_wp);
	op = t_wp_op;

	if ((opnd2 = *++t_wp) == (char *)0)
		syntax(op->op_text, "argument expected");
		
	switch (op->op_num) {
	case STREQ:
		return strcmp(opnd1, opnd2) == 0;
	case STRNE:
		return strcmp(opnd1, opnd2) != 0;
	case STRLT:
		return strcmp(opnd1, opnd2) < 0;
	case STRGT:
		return strcmp(opnd1, opnd2) > 0;
	case INTEQ:
		return getn(opnd1) == getn(opnd2);
	case INTNE:
		return getn(opnd1) != getn(opnd2);
	case INTGE:
		return getn(opnd1) >= getn(opnd2);
	case INTGT:
		return getn(opnd1) > getn(opnd2);
	case INTLE:
		return getn(opnd1) <= getn(opnd2);
	case INTLT:
		return getn(opnd1) < getn(opnd2);
	case FILNT:
		return newerf (opnd1, opnd2);
	case FILOT:
		return olderf (opnd1, opnd2);
	case FILEQ:
		return equalf (opnd1, opnd2);
	}
	/* NOTREACHED */
	return 1;
}

static int
filstat(nm, mode)
	char *nm;
	enum token mode;
{
	struct stat s;
	int i;

	if (mode == FILSYM) {
#ifdef S_IFLNK
		if (lstat(nm, &s) == 0) {
			i = S_IFLNK;
			goto filetype;
		}
#endif
		return 0;
	}

	if (stat(nm, &s) != 0) 
		return 0;

	switch (mode) {
	case FILRD:
		return test_eaccess(nm, R_OK) == 0;
	case FILWR:
		return test_eaccess(nm, W_OK) == 0;
	case FILEX:
		return test_eaccess(nm, X_OK) == 0;
	case FILEXIST:
		return 1;
	case FILREG:
		i = S_IFREG;
		goto filetype;
	case FILDIR:
		i = S_IFDIR;
		goto filetype;
	case FILCDEV:
		i = S_IFCHR;
		goto filetype;
	case FILBDEV:
		i = S_IFBLK;
		goto filetype;
	case FILFIFO:
#ifdef S_IFIFO
		i = S_IFIFO;
		goto filetype;
#else
		return 0;
#endif
	case FILSOCK:
#ifdef S_IFSOCK
		i = S_IFSOCK;
		goto filetype;
#else
		return 0;
#endif
	case FILSUID:
		i = S_ISUID;
		goto filebit;
	case FILSGID:
		i = S_ISGID;
		goto filebit;
	case FILSTCK:
		i = S_ISVTX;
		goto filebit;
	case FILGZ:
		return s.st_size > 0L;
	case FILUID:
		return s.st_uid == geteuid();
	case FILGID:
		return s.st_gid == getegid();
	default:
		return 1;
	}

filetype:
	return ((s.st_mode & S_IFMT) == i);

filebit:
	return ((s.st_mode & i) != 0);
}

static enum token
t_lex(s)
	char *s;
{
	struct t_op const *op = ops;

	if (s == 0) {
		t_wp_op = (struct t_op *)0;
		return EOI;
	}
	while (op->op_text) {
		if (strcmp(s, op->op_text) == 0) {
			t_wp_op = op;
			return op->op_num;
		}
		op++;
	}
	t_wp_op = (struct t_op *)0;
	return OPERAND;
}

/* atoi with error detection */
static int
getn(s)
	char *s;
{
	char *p;
	long r;

	errno = 0;
	r = strtol(s, &p, 10);

	if (errno != 0)
	  fatalError("%s: out of range\n", s);

	while (isspace(*p))
	  p++;
	
	if (*p)
	  fatalError("%s: bad number\n", s);

	return (int) r;
}

static int
newerf (f1, f2)
char *f1, *f2;
{
	struct stat b1, b2;

	return (stat (f1, &b1) == 0 &&
		stat (f2, &b2) == 0 &&
		b1.st_mtime > b2.st_mtime);
}

static int
olderf (f1, f2)
char *f1, *f2;
{
	struct stat b1, b2;

	return (stat (f1, &b1) == 0 &&
		stat (f2, &b2) == 0 &&
		b1.st_mtime < b2.st_mtime);
}

static int
equalf (f1, f2)
char *f1, *f2;
{
	struct stat b1, b2;

	return (stat (f1, &b1) == 0 &&
		stat (f2, &b2) == 0 &&
		b1.st_dev == b2.st_dev &&
		b1.st_ino == b2.st_ino);
}

/* Do the same thing access(2) does, but use the effective uid and gid,
   and don't make the mistake of telling root that any file is
   executable. */
static int
test_eaccess (path, mode)
char *path;
int mode;
{
	struct stat st;
	int euid = geteuid();

	if (stat (path, &st) < 0)
		return (-1);

	if (euid == 0) {
		/* Root can read or write any file. */
		if (mode != X_OK)
		return (0);

		/* Root can execute any file that has any one of the execute
		   bits set. */
		if (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))
			return (0);
	}

	if (st.st_uid == euid)		/* owner */
		mode <<= 6;
	else if (is_a_group_member (st.st_gid))
		mode <<= 3;

	if (st.st_mode & mode)
		return (0);

	return (-1);
}

static void
initialize_group_array ()
{
	ngroups = getgroups(0, NULL);
	if ((group_array = realloc(group_array, ngroups * sizeof(gid_t))) == NULL)
		fatalError("Out of space\n");

	getgroups(ngroups, group_array);
}

/* Return non-zero if GID is one that we have in our groups list. */
static int
is_a_group_member (gid)
gid_t gid;
{
	register int i;

	/* Short-circuit if possible, maybe saving a call to getgroups(). */
	if (gid == getgid() || gid == getegid())
		return (1);

	if (ngroups == 0)
		initialize_group_array ();

	/* Search through the list looking for GID. */
	for (i = 0; i < ngroups; i++)
		if (gid == group_array[i])
			return (1);

	return (0);
}