aboutsummaryrefslogtreecommitdiff
path: root/bin/ksh/c_test.c
blob: b48e4c117f4e6ad732847e6d8aaebfcce920e00a (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
/*	$OpenBSD: c_test.c,v 1.23 2015/12/14 13:59:42 tb Exp $	*/

/*
 * 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 Michael Rendell to add Korn's [[ .. ]] expressions.
 * modified by J.T. Conklin to add POSIX compatibility.
 */

#include <sys/stat.h>

#include <string.h>
#include <unistd.h>

#include "sh.h"
#include "c_test.h"

/* test(1) accepts the following grammar:
	oexpr	::= aexpr | aexpr "-o" oexpr ;
	aexpr	::= nexpr | nexpr "-a" aexpr ;
	nexpr	::= primary | "!" nexpr ;
	primary	::= unary-operator operand
		| operand binary-operator operand
		| operand
		| "(" oexpr ")"
		;

	unary-operator ::= "-a"|"-r"|"-w"|"-x"|"-e"|"-f"|"-d"|"-c"|"-b"|"-p"|
			   "-u"|"-g"|"-k"|"-s"|"-t"|"-z"|"-n"|"-o"|"-O"|"-G"|
			   "-L"|"-h"|"-S"|"-H";

	binary-operator ::= "="|"=="|"!="|"-eq"|"-ne"|"-ge"|"-gt"|"-le"|"-lt"|
			    "-nt"|"-ot"|"-ef"|
			    "<"|">"	# rules used for [[ .. ]] expressions
			    ;
	operand ::= <any thing>
*/

#define T_ERR_EXIT	2	/* POSIX says > 1 for errors */

struct t_op {
	char	op_text[4];
	Test_op	op_num;
};
static const struct t_op u_ops [] = {
	{"-a",	TO_FILAXST },
	{"-b",	TO_FILBDEV },
	{"-c",	TO_FILCDEV },
	{"-d",	TO_FILID },
	{"-e",	TO_FILEXST },
	{"-f",	TO_FILREG },
	{"-G",	TO_FILGID },
	{"-g",	TO_FILSETG },
	{"-h",	TO_FILSYM },
	{"-H",	TO_FILCDF },
	{"-k",	TO_FILSTCK },
	{"-L",	TO_FILSYM },
	{"-n",	TO_STNZE },
	{"-O",	TO_FILUID },
	{"-o",	TO_OPTION },
	{"-p",	TO_FILFIFO },
	{"-r",	TO_FILRD },
	{"-s",	TO_FILGZ },
	{"-S",	TO_FILSOCK },
	{"-t",	TO_FILTT },
	{"-u",	TO_FILSETU },
	{"-w",	TO_FILWR },
	{"-x",	TO_FILEX },
	{"-z",	TO_STZER },
	{"",	TO_NONOP }
};
static const struct t_op b_ops [] = {
	{"=",	TO_STEQL },
	{"==",	TO_STEQL },
	{"!=",	TO_STNEQ },
	{"<",	TO_STLT },
	{">",	TO_STGT },
	{"-eq",	TO_INTEQ },
	{"-ne",	TO_INTNE },
	{"-gt",	TO_INTGT },
	{"-ge",	TO_INTGE },
	{"-lt",	TO_INTLT },
	{"-le",	TO_INTLE },
	{"-ef",	TO_FILEQ },
	{"-nt",	TO_FILNT },
	{"-ot",	TO_FILOT },
	{"",	TO_NONOP }
};

static int	test_stat(const char *, struct stat *);
static int	test_eaccess(const char *, int);
static int	test_oexpr(Test_env *, int);
static int	test_aexpr(Test_env *, int);
static int	test_nexpr(Test_env *, int);
static int	test_primary(Test_env *, int);
static int	ptest_isa(Test_env *, Test_meta);
static const char *ptest_getopnd(Test_env *, Test_op, int);
static int	ptest_eval(Test_env *, Test_op, const char *,
		    const char *, int);
static void	ptest_error(Test_env *, int, const char *);

int
c_test(char **wp)
{
	int argc;
	int res;
	Test_env te;

	te.flags = 0;
	te.isa = ptest_isa;
	te.getopnd = ptest_getopnd;
	te.eval = ptest_eval;
	te.error = ptest_error;

	for (argc = 0; wp[argc]; argc++)
		;

	if (strcmp(wp[0], "[") == 0) {
		if (strcmp(wp[--argc], "]") != 0) {
			bi_errorf("missing ]");
			return T_ERR_EXIT;
		}
	}

	te.pos.wp = wp + 1;
	te.wp_end = wp + argc;

	/*
	 * Handle the special cases from POSIX.2, section 4.62.4.
	 * Implementation of all the rules isn't necessary since
	 * our parser does the right thing for the omitted steps.
	 */
	if (argc <= 5) {
		char **owp = wp;
		int invert = 0;
		Test_op	op;
		const char *opnd1, *opnd2;

		while (--argc >= 0) {
			if ((*te.isa)(&te, TM_END))
				return !0;
			if (argc == 3) {
				opnd1 = (*te.getopnd)(&te, TO_NONOP, 1);
				if ((op = (Test_op) (*te.isa)(&te, TM_BINOP))) {
					opnd2 = (*te.getopnd)(&te, op, 1);
					res = (*te.eval)(&te, op, opnd1,
					    opnd2, 1);
					if (te.flags & TEF_ERROR)
						return T_ERR_EXIT;
					if (invert & 1)
						res = !res;
					return !res;
				}
				/* back up to opnd1 */
				te.pos.wp--;
			}
			if (argc == 1) {
				opnd1 = (*te.getopnd)(&te, TO_NONOP, 1);
				/* Historically, -t by itself test if fd 1
				 * is a file descriptor, but POSIX says its
				 * a string test...
				 */
				if (!Flag(FPOSIX) && strcmp(opnd1, "-t") == 0)
				    break;
				res = (*te.eval)(&te, TO_STNZE, opnd1,
				    NULL, 1);
				if (invert & 1)
					res = !res;
				return !res;
			}
			if ((*te.isa)(&te, TM_NOT)) {
				invert++;
			} else
				break;
		}
		te.pos.wp = owp + 1;
	}

	return test_parse(&te);
}

/*
 * Generic test routines.
 */

Test_op
test_isop(Test_env *te, Test_meta meta, const char *s)
{
	char sc1;
	const struct t_op *otab;

	otab = meta == TM_UNOP ? u_ops : b_ops;
	if (*s) {
		sc1 = s[1];
		for (; otab->op_text[0]; otab++)
			if (sc1 == otab->op_text[1] &&
			    strcmp(s, otab->op_text) == 0 &&
			    ((te->flags & TEF_DBRACKET) ||
			    (otab->op_num != TO_STLT && otab->op_num != TO_STGT)))
				return otab->op_num;
	}
	return TO_NONOP;
}

int
test_eval(Test_env *te, Test_op op, const char *opnd1, const char *opnd2,
    int do_eval)
{
	int res;
	int not;
	struct stat b1, b2;

	if (!do_eval)
		return 0;

	switch ((int) op) {
	/*
	 * Unary Operators
	 */
	case TO_STNZE: /* -n */
		return *opnd1 != '\0';
	case TO_STZER: /* -z */
		return *opnd1 == '\0';
	case TO_OPTION: /* -o */
		if ((not = *opnd1 == '!'))
			opnd1++;
		if ((res = option(opnd1)) < 0)
			res = 0;
		else {
			res = Flag(res);
			if (not)
				res = !res;
		}
		return res;
	case TO_FILRD: /* -r */
		return test_eaccess(opnd1, R_OK) == 0;
	case TO_FILWR: /* -w */
		return test_eaccess(opnd1, W_OK) == 0;
	case TO_FILEX: /* -x */
		return test_eaccess(opnd1, X_OK) == 0;
	case TO_FILAXST: /* -a */
		return test_stat(opnd1, &b1) == 0;
	case TO_FILEXST: /* -e */
		/* at&t ksh does not appear to do the /dev/fd/ thing for
		 * this (unless the os itself handles it)
		 */
		return stat(opnd1, &b1) == 0;
	case TO_FILREG: /* -r */
		return test_stat(opnd1, &b1) == 0 && S_ISREG(b1.st_mode);
	case TO_FILID: /* -d */
		return test_stat(opnd1, &b1) == 0 && S_ISDIR(b1.st_mode);
	case TO_FILCDEV: /* -c */
		return test_stat(opnd1, &b1) == 0 && S_ISCHR(b1.st_mode);
	case TO_FILBDEV: /* -b */
		return test_stat(opnd1, &b1) == 0 && S_ISBLK(b1.st_mode);
	case TO_FILFIFO: /* -p */
		return test_stat(opnd1, &b1) == 0 && S_ISFIFO(b1.st_mode);
	case TO_FILSYM: /* -h -L */
		return lstat(opnd1, &b1) == 0 && S_ISLNK(b1.st_mode);
	case TO_FILSOCK: /* -S */
		return test_stat(opnd1, &b1) == 0 && S_ISSOCK(b1.st_mode);
	case TO_FILCDF:/* -H HP context dependent files (directories) */
		return 0;
	case TO_FILSETU: /* -u */
		return test_stat(opnd1, &b1) == 0 &&
		    (b1.st_mode & S_ISUID) == S_ISUID;
	case TO_FILSETG: /* -g */
		return test_stat(opnd1, &b1) == 0 &&
		    (b1.st_mode & S_ISGID) == S_ISGID;
	case TO_FILSTCK: /* -k */
		return test_stat(opnd1, &b1) == 0 &&
		    (b1.st_mode & S_ISVTX) == S_ISVTX;
	case TO_FILGZ: /* -s */
		return test_stat(opnd1, &b1) == 0 && b1.st_size > 0L;
	case TO_FILTT: /* -t */
		if (opnd1 && !bi_getn(opnd1, &res)) {
			te->flags |= TEF_ERROR;
			res = 0;
		} else {
			/* generate error if in FPOSIX mode? */
			res = isatty(opnd1 ? res : 0);
		}
		return res;
	case TO_FILUID: /* -O */
		return test_stat(opnd1, &b1) == 0 && b1.st_uid == ksheuid;
	case TO_FILGID: /* -G */
		return test_stat(opnd1, &b1) == 0 && b1.st_gid == getegid();
	/*
	 * Binary Operators
	 */
	case TO_STEQL: /* = */
		if (te->flags & TEF_DBRACKET)
			return gmatch(opnd1, opnd2, false);
		return strcmp(opnd1, opnd2) == 0;
	case TO_STNEQ: /* != */
		if (te->flags & TEF_DBRACKET)
			return !gmatch(opnd1, opnd2, false);
		return strcmp(opnd1, opnd2) != 0;
	case TO_STLT: /* < */
		return strcmp(opnd1, opnd2) < 0;
	case TO_STGT: /* > */
		return strcmp(opnd1, opnd2) > 0;
	case TO_INTEQ: /* -eq */
	case TO_INTNE: /* -ne */
	case TO_INTGE: /* -ge */
	case TO_INTGT: /* -gt */
	case TO_INTLE: /* -le */
	case TO_INTLT: /* -lt */
		{
			long v1, v2;

			if (!evaluate(opnd1, &v1, KSH_RETURN_ERROR, false) ||
			    !evaluate(opnd2, &v2, KSH_RETURN_ERROR, false)) {
				/* error already printed.. */
				te->flags |= TEF_ERROR;
				return 1;
			}
			switch ((int) op) {
			case TO_INTEQ:
				return v1 == v2;
			case TO_INTNE:
				return v1 != v2;
			case TO_INTGE:
				return v1 >= v2;
			case TO_INTGT:
				return v1 > v2;
			case TO_INTLE:
				return v1 <= v2;
			case TO_INTLT:
				return v1 < v2;
			}
		}
	case TO_FILNT: /* -nt */
		{
			int s2;
			/* ksh88/ksh93 succeed if file2 can't be stated
			 * (subtly different from `does not exist').
			 */
			return stat(opnd1, &b1) == 0 &&
			    (((s2 = stat(opnd2, &b2)) == 0 &&
			    b1.st_mtime > b2.st_mtime) || s2 < 0);
		}
	case TO_FILOT: /* -ot */
		{
			int s1;
			/* ksh88/ksh93 succeed if file1 can't be stated
			 * (subtly different from `does not exist').
			 */
			return stat(opnd2, &b2) == 0 &&
			    (((s1 = stat(opnd1, &b1)) == 0 &&
			    b1.st_mtime < b2.st_mtime) || s1 < 0);
		}
	case TO_FILEQ: /* -ef */
		return stat (opnd1, &b1) == 0 && stat (opnd2, &b2) == 0 &&
		    b1.st_dev == b2.st_dev && b1.st_ino == b2.st_ino;
	}
	(*te->error)(te, 0, "internal error: unknown op");
	return 1;
}

/* Nasty kludge to handle Korn's bizarre /dev/fd hack */
static int
test_stat(const char *path, struct stat *statb)
{
	return stat(path, statb);
}

/* Routine to handle Korn's /dev/fd hack, and to deal with X_OK on
 * non-directories when running as root.
 */
static int
test_eaccess(const char *path, int mode)
{
	int res;

	res = access(path, mode);
	/*
	 * On most (all?) unixes, access() says everything is executable for
	 * root - avoid this on files by using stat().
	 */
	if (res == 0 && ksheuid == 0 && (mode & X_OK)) {
		struct stat statb;

		if (stat(path, &statb) < 0)
			res = -1;
		else if (S_ISDIR(statb.st_mode))
			res = 0;
		else
			res = (statb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) ?
			    0 : -1;
	}

	return res;
}

int
test_parse(Test_env *te)
{
	int res;

	res = test_oexpr(te, 1);

	if (!(te->flags & TEF_ERROR) && !(*te->isa)(te, TM_END))
		(*te->error)(te, 0, "unexpected operator/operand");

	return (te->flags & TEF_ERROR) ? T_ERR_EXIT : !res;
}

static int
test_oexpr(Test_env *te, int do_eval)
{
	int res;

	res = test_aexpr(te, do_eval);
	if (res)
		do_eval = 0;
	if (!(te->flags & TEF_ERROR) && (*te->isa)(te, TM_OR))
		return test_oexpr(te, do_eval) || res;
	return res;
}

static int
test_aexpr(Test_env *te, int do_eval)
{
	int res;

	res = test_nexpr(te, do_eval);
	if (!res)
		do_eval = 0;
	if (!(te->flags & TEF_ERROR) && (*te->isa)(te, TM_AND))
		return test_aexpr(te, do_eval) && res;
	return res;
}

static int
test_nexpr(Test_env *te, int do_eval)
{
	if (!(te->flags & TEF_ERROR) && (*te->isa)(te, TM_NOT))
		return !test_nexpr(te, do_eval);
	return test_primary(te, do_eval);
}

static int
test_primary(Test_env *te, int do_eval)
{
	const char *opnd1, *opnd2;
	int res;
	Test_op op;

	if (te->flags & TEF_ERROR)
		return 0;
	if ((*te->isa)(te, TM_OPAREN)) {
		res = test_oexpr(te, do_eval);
		if (te->flags & TEF_ERROR)
			return 0;
		if (!(*te->isa)(te, TM_CPAREN)) {
			(*te->error)(te, 0, "missing closing paren");
			return 0;
		}
		return res;
	}
	/*
	 * Binary should have precedence over unary in this case
	 * so that something like test \( -f = -f \) is accepted
	 */
	if ((te->flags & TEF_DBRACKET) || (&te->pos.wp[1] < te->wp_end &&
	    !test_isop(te, TM_BINOP, te->pos.wp[1]))) {
		if ((op = (Test_op) (*te->isa)(te, TM_UNOP))) {
			/* unary expression */
			opnd1 = (*te->getopnd)(te, op, do_eval);
			if (!opnd1) {
				(*te->error)(te, -1, "missing argument");
				return 0;
			}

			return (*te->eval)(te, op, opnd1, NULL,
			    do_eval);
		}
	}
	opnd1 = (*te->getopnd)(te, TO_NONOP, do_eval);
	if (!opnd1) {
		(*te->error)(te, 0, "expression expected");
		return 0;
	}
	if ((op = (Test_op) (*te->isa)(te, TM_BINOP))) {
		/* binary expression */
		opnd2 = (*te->getopnd)(te, op, do_eval);
		if (!opnd2) {
			(*te->error)(te, -1, "missing second argument");
			return 0;
		}

		return (*te->eval)(te, op, opnd1, opnd2, do_eval);
	}
	if (te->flags & TEF_DBRACKET) {
		(*te->error)(te, -1, "missing expression operator");
		return 0;
	}
	return (*te->eval)(te, TO_STNZE, opnd1, NULL, do_eval);
}

/*
 * Plain test (test and [ .. ]) specific routines.
 */

/* Test if the current token is a whatever.  Accepts the current token if
 * it is.  Returns 0 if it is not, non-zero if it is (in the case of
 * TM_UNOP and TM_BINOP, the returned value is a Test_op).
 */
static int
ptest_isa(Test_env *te, Test_meta meta)
{
	/* Order important - indexed by Test_meta values */
	static const char *const tokens[] = {
		"-o", "-a", "!", "(", ")"
	};
	int ret;

	if (te->pos.wp >= te->wp_end)
		return meta == TM_END;

	if (meta == TM_UNOP || meta == TM_BINOP)
		ret = (int) test_isop(te, meta, *te->pos.wp);
	else if (meta == TM_END)
		ret = 0;
	else
		ret = strcmp(*te->pos.wp, tokens[(int) meta]) == 0;

	/* Accept the token? */
	if (ret)
		te->pos.wp++;

	return ret;
}

static const char *
ptest_getopnd(Test_env *te, Test_op op, int do_eval)
{
	if (te->pos.wp >= te->wp_end)
		return op == TO_FILTT ? "1" : NULL;
	return *te->pos.wp++;
}

static int
ptest_eval(Test_env *te, Test_op op, const char *opnd1, const char *opnd2,
    int do_eval)
{
	return test_eval(te, op, opnd1, opnd2, do_eval);
}

static void
ptest_error(Test_env *te, int offset, const char *msg)
{
	const char *op = te->pos.wp + offset >= te->wp_end ?
	    NULL : te->pos.wp[offset];

	te->flags |= TEF_ERROR;
	if (op)
		bi_errorf("%s: %s", op, msg);
	else
		bi_errorf("%s", msg);
}