summaryrefslogtreecommitdiff
path: root/src/test.c
blob: 9cd691acf5d05e9aef8de160dd1d42ef3423d6d2 (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
/* GNU test program (ksb and mjb) */

/* Modified to run with the GNU shell by bfox. */

/* Copyright (C) 1987-2003 Free Software Foundation, Inc.

   This file is part of GNU Bash, the Bourne Again SHell.

   Bash 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, or (at your option) any later
   version.

   Bash 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.  */

/* Define TEST_STANDALONE to get the /bin/test version.  Otherwise, you get
   the shell builtin version. */

#include <config.h>
#include <stdio.h>
#include <sys/types.h>

#define TEST_STANDALONE 1

#ifndef LBRACKET
# define LBRACKET 0
#endif

/* The official name of this program (e.g., no `g' prefix).  */
#if LBRACKET
# define PROGRAM_NAME "["
#else
# define PROGRAM_NAME "test"
#endif

#include "system.h"
#include "error.h"
#include "exitfail.h"
#include "euidaccess.h"

#ifndef _POSIX_VERSION
# include <sys/param.h>
#endif /* _POSIX_VERSION */
#define whitespace(c) (((c) == ' ') || ((c) == '\t'))
#define digit(c)  ((c) >= '0' && (c) <= '9')
#define digit_value(c) ((c) - '0')

char *program_name;

#if !defined (_POSIX_VERSION)
# include <sys/file.h>
#endif /* !_POSIX_VERSION */

extern gid_t getegid ();
extern uid_t geteuid ();

#if !defined (R_OK)
# define R_OK 4
# define W_OK 2
# define X_OK 1
# define F_OK 0
#endif /* R_OK */

/* The following few defines control the truth and false output of each stage.
   TRUE and FALSE are what we use to compute the final output value.
   SHELL_BOOLEAN is the form which returns truth or falseness in shell terms.
   TRUTH_OR is how to do logical or with TRUE and FALSE.
   TRUTH_AND is how to do logical and with TRUE and FALSE..
   Default is TRUE = 1, FALSE = 0, TRUTH_OR = a | b, TRUTH_AND = a & b,
    SHELL_BOOLEAN = (!value). */
#define TRUE 1
#define FALSE 0
#define SHELL_BOOLEAN(value) (!(value))
#define TRUTH_OR(a, b) ((a) | (b))
#define TRUTH_AND(a, b) ((a) & (b))

/* Exit status for syntax errors, etc.  */
enum { TEST_FAILURE = 2 };

#if defined (TEST_STANDALONE)
# define test_exit(val) exit (val)
#else
   static jmp_buf test_exit_buf;
   static int test_error_return = 0;
# define test_exit(val) test_error_return = val, longjmp (test_exit_buf, 1)
#endif /* !TEST_STANDALONE */

static int pos;		/* The offset of the current argument in ARGV. */
static int argc;	/* The number of arguments present in ARGV. */
static char **argv;	/* The argument list. */

static int test_unop (char const *s);
static int binop (char *s);
static int unary_operator (void);
static int binary_operator (bool);
static int two_arguments (void);
static int three_arguments (void);
static int posixtest (int);

static int expr (void);
static int term (void);
static int and (void);
static int or (void);

static void test_syntax_error (char const *format, char const *arg)
     ATTRIBUTE_NORETURN;
static void beyond (void) ATTRIBUTE_NORETURN;

static void
test_syntax_error (char const *format, char const *arg)
{
  fprintf (stderr, "%s: ", argv[0]);
  fprintf (stderr, format, arg);
  fflush (stderr);
  test_exit (TEST_FAILURE);
}

#if HAVE_SETREUID && HAVE_SETREGID
/* Do the same thing access(2) does, but use the effective uid and gid.  */

static int
eaccess (char const *file, int mode)
{
  static int have_ids;
  static uid_t uid, euid;
  static gid_t gid, egid;
  int result;

  if (have_ids == 0)
    {
      have_ids = 1;
      uid = getuid ();
      gid = getgid ();
      euid = geteuid ();
      egid = getegid ();
    }

  /* Set the real user and group IDs to the effective ones.  */
  if (uid != euid)
    setreuid (euid, uid);
  if (gid != egid)
    setregid (egid, gid);

  result = access (file, mode);

  /* Restore them.  */
  if (uid != euid)
    setreuid (uid, euid);
  if (gid != egid)
    setregid (gid, egid);

  return result;
}
#else
# define eaccess(F, M) euidaccess (F, M)
#endif

/* Increment our position in the argument list.  Check that we're not
   past the end of the argument list.  This check is supressed if the
   argument is FALSE.  Made a macro for efficiency. */
#define advance(f)							\
  do									\
    {									\
      ++pos;								\
      if ((f) && pos >= argc)						\
	beyond ();							\
    }									\
  while (0)

#if !defined (advance)
static int
advance (int f)
{
  ++pos;

  if (f && pos >= argc)
    beyond ();
}
#endif /* advance */

#define unary_advance()							\
  do									\
    {									\
      advance (1);							\
      ++pos;								\
    }									\
  while (0)

/*
 * beyond - call when we're beyond the end of the argument list (an
 *	error condition)
 */
static void
beyond (void)
{
  test_syntax_error (_("argument expected\n"), NULL);
}

/* Syntax error for when an integer argument was expected, but
   something else was found. */
static void
integer_expected_error (char const *pch)
{
  test_syntax_error (_("%s: integer expression expected\n"), pch);
}

/* Return nonzero if the characters pointed to by STRING constitute a
   valid number.  Stuff the converted number into RESULT if RESULT is
   not null.  */
static int
isint (register char *string, intmax_t *result)
{
  int sign;
  intmax_t value;

  sign = 1;
  value = 0;

  if (result)
    *result = 0;

  /* Skip leading whitespace characters. */
  while (whitespace (*string))
    string++;

  if (!*string)
    return (0);

  /* We allow leading `-' or `+'. */
  if (*string == '-' || *string == '+')
    {
      if (!digit (string[1]))
	return (0);

      if (*string == '-')
	sign = -1;

      string++;
    }

  while (digit (*string))
    {
      if (result)
	value = (value * 10) + digit_value (*string);
      string++;
    }

  /* Skip trailing whitespace, if any. */
  while (whitespace (*string))
    string++;

  /* Error if not at end of string. */
  if (*string)
    return (0);

  if (result)
    {
      value *= sign;
      *result = value;
    }

  return (1);
}

/* Find the modification time of FILE, and stuff it into *AGE.
   Return 0 if successful, -1 if not.  */
static int
age_of (char *filename, time_t *age)
{
  struct stat finfo;
  int r = stat (filename, &finfo);
  if (r == 0)
    *age = finfo.st_mtime;
  return r;
}

/*
 * term - parse a term and return 1 or 0 depending on whether the term
 *	evaluates to true or false, respectively.
 *
 * term ::=
 *	'-'('h'|'d'|'f'|'r'|'s'|'w'|'c'|'b'|'p'|'u'|'g'|'k') filename
 *	'-'('L'|'x') filename
 *	'-t' [ int ]
 *	'-'('z'|'n') string
 *	string
 *	string ('!='|'=') string
 *	<int> '-'(eq|ne|le|lt|ge|gt) <int>
 *	file '-'(nt|ot|ef) file
 *	'(' <expr> ')'
 * int ::=
 *	'-l' string
 *	positive and negative integers
 */
static int
term (void)
{
  int value;

  if (pos >= argc)
    beyond ();

  /* Deal with leading `not's. */
  if (argv[pos][0] == '!' && argv[pos][1] == '\0')
    {
      value = 0;
      while (pos < argc && argv[pos][0] == '!' && argv[pos][1] == '\0')
	{
	  advance (1);
	  value = 1 - value;
	}

      return (value ? !term() : term());
    }

  /* A paren-bracketed argument. */
  if (argv[pos][0] == '(' && argv[pos][1] == '\0')
    {
      int nargs;

      advance (1);

      for (nargs = 1;
	   pos + nargs < argc && ! STREQ (argv[pos + nargs], ")");
	   nargs++)
	if (nargs == 4)
	  {
	    nargs = argc - pos;
	    break;
	  }

      value = posixtest (nargs);
      if (argv[pos] == 0)
	test_syntax_error (_("')' expected\n"), NULL);
      else
        if (argv[pos][0] != ')' || argv[pos][1])
	  test_syntax_error (_("')' expected, found %s\n"), argv[pos]);
      advance (0);
      return (value);
    }

  /* are there enough arguments left that this could be dyadic? */
  if (pos + 4 <= argc && STREQ (argv[pos], "-l") && binop (argv[pos + 2]))
    value = binary_operator (true);
  else if (pos + 3 <= argc && binop (argv[pos + 1]))
    value = binary_operator (false);

  /* Might be a switch type argument */
  else if (argv[pos][0] == '-' && argv[pos][1] && argv[pos][2] == '\0')
    {
      if (test_unop (argv[pos]))
	value = unary_operator ();
      else
	test_syntax_error (_("%s: unary operator expected\n"), argv[pos]);
    }
  else
    {
      value = (argv[pos][0] != '\0');
      advance (0);
    }

  return (value);
}

static int
binary_operator (bool l_is_l)
{
  register int op;
  struct stat stat_buf, stat_spare;
  intmax_t l, r;
  int value;
  /* Is the right integer expression of the form '-l string'? */
  int r_is_l;

  if (l_is_l)
    advance (0);
  op = pos + 1;

  if ((op < argc - 2) && (strcmp (argv[op + 1], "-l") == 0))
    {
      r_is_l = 1;
      advance (0);
    }
  else
    r_is_l = 0;

  if (argv[op][0] == '-')
    {
      /* check for eq, nt, and stuff */
      switch (argv[op][1])
	{
	default:
	  break;

	case 'l':
	  if (argv[op][2] == 't' && !argv[op][3])
	    {
	      /* lt */
	      if (l_is_l)
		l = strlen (argv[op - 1]);
	      else
		{
		  if (!isint (argv[op - 1], &l))
		    integer_expected_error (_("before -lt"));
		}

	      if (r_is_l)
		r = strlen (argv[op + 2]);
	      else
		{
		  if (!isint (argv[op + 1], &r))
		    integer_expected_error (_("after -lt"));
		}
	      pos += 3;
	      return (TRUE == (l < r));
	    }

	  if (argv[op][2] == 'e' && !argv[op][3])
	    {
	      /* le */
	      if (l_is_l)
		l = strlen (argv[op - 1]);
	      else
		{
		  if (!isint (argv[op - 1], &l))
		    integer_expected_error (_("before -le"));
		}
	      if (r_is_l)
		r = strlen (argv[op + 2]);
	      else
		{
		  if (!isint (argv[op + 1], &r))
		    integer_expected_error (_("after -le"));
		}
	      pos += 3;
	      return (TRUE == (l <= r));
	    }
	  break;

	case 'g':
	  if (argv[op][2] == 't' && !argv[op][3])
	    {
	      /* gt integer greater than */
	      if (l_is_l)
		l = strlen (argv[op - 1]);
	      else
		{
		  if (!isint (argv[op - 1], &l))
		    integer_expected_error (_("before -gt"));
		}
	      if (r_is_l)
		r = strlen (argv[op + 2]);
	      else
		{
		  if (!isint (argv[op + 1], &r))
		    integer_expected_error (_("after -gt"));
		}
	      pos += 3;
	      return (TRUE == (l > r));
	    }

	  if (argv[op][2] == 'e' && !argv[op][3])
	    {
	      /* ge - integer greater than or equal to */
	      if (l_is_l)
		l = strlen (argv[op - 1]);
	      else
		{
		  if (!isint (argv[op - 1], &l))
		    integer_expected_error (_("before -ge"));
		}
	      if (r_is_l)
		r = strlen (argv[op + 2]);
	      else
		{
		  if (!isint (argv[op + 1], &r))
		    integer_expected_error (_("after -ge"));
		}
	      pos += 3;
	      return (TRUE == (l >= r));
	    }
	  break;

	case 'n':
	  if (argv[op][2] == 't' && !argv[op][3])
	    {
	      /* nt - newer than */
	      time_t lt, rt;
	      int le, re;
	      pos += 3;
	      if (l_is_l || r_is_l)
		test_syntax_error (_("-nt does not accept -l\n"), NULL);
	      le = age_of (argv[op - 1], &lt);
	      re = age_of (argv[op + 1], &rt);
	      return le > re || (le == 0 && lt > rt);
	    }

	  if (argv[op][2] == 'e' && !argv[op][3])
	    {
	      /* ne - integer not equal */
	      if (l_is_l)
		l = strlen (argv[op - 1]);
	      else
		{
		  if (!isint (argv[op - 1], &l))
		    integer_expected_error (_("before -ne"));
		}
	      if (r_is_l)
		r = strlen (argv[op + 2]);
	      else
		{
		  if (!isint (argv[op + 1], &r))
		    integer_expected_error (_("after -ne"));
		}
	      pos += 3;
	      return (TRUE == (l != r));
	    }
	  break;

	case 'e':
	  if (argv[op][2] == 'q' && !argv[op][3])
	    {
	      /* eq - integer equal */
	      if (l_is_l)
		l = strlen (argv[op - 1]);
	      else
		{
		  if (!isint (argv[op - 1], &l))
		    integer_expected_error (_("before -eq"));
		}
	      if (r_is_l)
		r = strlen (argv[op + 2]);
	      else
		{
		  if (!isint (argv[op + 1], &r))
		    integer_expected_error (_("after -eq"));
		}
	      pos += 3;
	      return (TRUE == (l == r));
	    }

	  if (argv[op][2] == 'f' && !argv[op][3])
	    {
	      /* ef - hard link? */
	      pos += 3;
	      if (l_is_l || r_is_l)
		test_syntax_error (_("-ef does not accept -l\n"), NULL);
	      if (stat (argv[op - 1], &stat_buf) < 0)
		return (FALSE);
	      if (stat (argv[op + 1], &stat_spare) < 0)
		return (FALSE);
	      return (TRUE ==
		      (stat_buf.st_dev == stat_spare.st_dev &&
		       stat_buf.st_ino == stat_spare.st_ino));
	    }
	  break;

	case 'o':
	  if ('t' == argv[op][2] && '\000' == argv[op][3])
	    {
	      /* ot - older than */
	      time_t lt, rt;
	      int le, re;
	      pos += 3;
	      if (l_is_l || r_is_l)
		test_syntax_error (_("-ot does not accept -l\n"), NULL);
	      le = age_of (argv[op - 1], &lt);
	      re = age_of (argv[op + 1], &rt);
	      return le < re || (re == 0 && lt < rt);
	    }
	  break;
	}

      /* FIXME: is this dead code? */
      test_syntax_error (_("unknown binary operator\n"), argv[op]);
    }

  if (argv[op][0] == '=' && !argv[op][1])
    {
      value = (strcmp (argv[pos], argv[pos + 2]) == 0);
      pos += 3;
      return (TRUE == value);
    }

  if (strcmp (argv[op], "!=") == 0)
    {
      value = (strcmp (argv[pos], argv[pos + 2]) != 0);
      pos += 3;
      return (TRUE == value);
    }

  /* Not reached.  */
  abort ();
}

static int
unary_operator (void)
{
  int value;
  struct stat stat_buf;

  switch (argv[pos][1])
    {
    default:
      return (FALSE);

      /* All of the following unary operators use unary_advance (), which
	 checks to make sure that there is an argument, and then advances
	 pos right past it.  This means that pos - 1 is the location of the
	 argument. */

    case 'a':			/* file exists in the file system? */
    case 'e':
      unary_advance ();
      value = -1 != stat (argv[pos - 1], &stat_buf);
      return (TRUE == value);

    case 'r':			/* file is readable? */
      unary_advance ();
      value = -1 != eaccess (argv[pos - 1], R_OK);
      return (TRUE == value);

    case 'w':			/* File is writable? */
      unary_advance ();
      value = -1 != eaccess (argv[pos - 1], W_OK);
      return (TRUE == value);

    case 'x':			/* File is executable? */
      unary_advance ();
      value = -1 != eaccess (argv[pos - 1], X_OK);
      return (TRUE == value);

    case 'O':			/* File is owned by you? */
      unary_advance ();
      if (stat (argv[pos - 1], &stat_buf) < 0)
	return (FALSE);

      return (TRUE == (geteuid () == stat_buf.st_uid));

    case 'G':			/* File is owned by your group? */
      unary_advance ();
      if (stat (argv[pos - 1], &stat_buf) < 0)
	return (FALSE);

      return (TRUE == (getegid () == stat_buf.st_gid));

    case 'f':			/* File is a file? */
      unary_advance ();
      if (stat (argv[pos - 1], &stat_buf) < 0)
	return (FALSE);

      /* Under POSIX, -f is true if the given file exists
	 and is a regular file. */
      return (TRUE == ((S_ISREG (stat_buf.st_mode)) ||
		       (0 == (stat_buf.st_mode & S_IFMT))));

    case 'd':			/* File is a directory? */
      unary_advance ();
      if (stat (argv[pos - 1], &stat_buf) < 0)
	return (FALSE);

      return (TRUE == (S_ISDIR (stat_buf.st_mode)));

    case 's':			/* File has something in it? */
      unary_advance ();
      if (stat (argv[pos - 1], &stat_buf) < 0)
	return (FALSE);

      return (TRUE == (stat_buf.st_size > (off_t) 0));

    case 'S':			/* File is a socket? */
#if !defined (S_ISSOCK)
      return (FALSE);
#else
      unary_advance ();

      if (stat (argv[pos - 1], &stat_buf) < 0)
	return (FALSE);

      return (TRUE == (S_ISSOCK (stat_buf.st_mode)));
#endif				/* S_ISSOCK */

    case 'c':			/* File is character special? */
      unary_advance ();
      if (stat (argv[pos - 1], &stat_buf) < 0)
	return (FALSE);

      return (TRUE == (S_ISCHR (stat_buf.st_mode)));

    case 'b':			/* File is block special? */
      unary_advance ();
      if (stat (argv[pos - 1], &stat_buf) < 0)
	return (FALSE);

      return (TRUE == (S_ISBLK (stat_buf.st_mode)));

    case 'p':			/* File is a named pipe? */
      unary_advance ();
#ifndef S_ISFIFO
      return (FALSE);
#else
      if (stat (argv[pos - 1], &stat_buf) < 0)
	return (FALSE);
      return (TRUE == (S_ISFIFO (stat_buf.st_mode)));
#endif				/* S_ISFIFO */

    case 'L':			/* Same as -h  */
      /*FALLTHROUGH*/

    case 'h':			/* File is a symbolic link? */
      unary_advance ();
#ifndef S_ISLNK
      return (FALSE);
#else
      /* An empty filename is not a valid pathname. */
      if ((argv[pos - 1][0] == '\0') ||
	  (lstat (argv[pos - 1], &stat_buf) < 0))
	return (FALSE);

      return (TRUE == (S_ISLNK (stat_buf.st_mode)));
#endif				/* S_IFLNK */

    case 'u':			/* File is setuid? */
      unary_advance ();
#ifndef S_ISUID
      return (FALSE);
#else
      if (stat (argv[pos - 1], &stat_buf) < 0)
	return (FALSE);

      return (TRUE == (0 != (stat_buf.st_mode & S_ISUID)));
#endif

    case 'g':			/* File is setgid? */
      unary_advance ();
#ifndef S_ISGID
      return (FALSE);
#else
      if (stat (argv[pos - 1], &stat_buf) < 0)
	return (FALSE);

      return (TRUE == (0 != (stat_buf.st_mode & S_ISGID)));
#endif

    case 'k':			/* File has sticky bit set? */
      unary_advance ();
      if (stat (argv[pos - 1], &stat_buf) < 0)
	return (FALSE);
#ifndef S_ISVTX
      /* This is not Posix, and is not defined on some Posix systems. */
      return (FALSE);
#else
      return (TRUE == (0 != (stat_buf.st_mode & S_ISVTX)));
#endif

    case 't':			/* File (fd) is a terminal? */
      {
	intmax_t fd;
	unary_advance ();
	if (!isint (argv[pos - 1], &fd))
	  integer_expected_error (_("after -t"));
	return (TRUE == (fd == (int) fd && isatty (fd)));
      }

    case 'n':			/* True if arg has some length. */
      unary_advance ();
      return (TRUE == (argv[pos - 1][0] != 0));

    case 'z':			/* True if arg has no length. */
      unary_advance ();
      return (TRUE == (argv[pos - 1][0] == '\0'));
    }
}

/*
 * and:
 *	term
 *	term '-a' and
 */
static int
and (void)
{
  int value;

  value = term ();
  while ((pos < argc) && strcmp (argv[pos], "-a") == 0)
    {
      advance (0);
      value = TRUTH_AND (value, and ());
    }
  return (TRUE == value);
}

/*
 * or:
 *	and
 *	and '-o' or
 */
static int
or (void)
{
  int value;

  value = and ();

  while ((pos < argc) && strcmp (argv[pos], "-o") == 0)
    {
      advance (0);
      value = TRUTH_OR (value, or ());
    }

  return (TRUE == value);
}

/*
 * expr:
 *	or
 */
static int
expr (void)
{
  if (pos >= argc)
    beyond ();

  return (FALSE ^ (or ()));		/* Same with this. */
}

/* Return TRUE if S is one of the test command's binary operators. */
static int
binop (char *s)
{
  return ((STREQ (s,   "=")) || (STREQ (s,  "!=")) || (STREQ (s, "-nt")) ||
	  (STREQ (s, "-ot")) || (STREQ (s, "-ef")) || (STREQ (s, "-eq")) ||
	  (STREQ (s, "-ne")) || (STREQ (s, "-lt")) || (STREQ (s, "-le")) ||
	  (STREQ (s, "-gt")) || (STREQ (s, "-ge")));
}

/* Return nonzero if OP is one of the test command's unary operators. */
static int
test_unop (char const *op)
{
  if (op[0] != '-')
    return (0);

  switch (op[1])
    {
    case 'a': case 'b': case 'c': case 'd': case 'e':
    case 'f': case 'g': case 'h': case 'k': case 'n':
    case 'o': case 'p': case 'r': case 's': case 't':
    case 'u': case 'w': case 'x': case 'z':
    case 'G': case 'L': case 'O': case 'S': case 'N':
      return (1);
    }

  return (0);
}

static int
one_argument (void)
{
  return argv[pos++][0] != '\0';
}

static int
two_arguments (void)
{
  int value;

  if (STREQ (argv[pos], "!"))
    {
      advance (0);
      value = ! one_argument ();
    }
  else if (argv[pos][0] == '-'
	   && argv[pos][1] != '\0'
	   && argv[pos][2] == '\0')
    {
      if (test_unop (argv[pos]))
	value = unary_operator ();
      else
	test_syntax_error (_("%s: unary operator expected\n"), argv[pos]);
    }
  else
    beyond ();
  return (value);
}

static int
three_arguments (void)
{
  int value;

  if (binop (argv[pos + 1]))
    value = binary_operator (false);
  else if (STREQ (argv[pos], "!"))
    {
      advance (1);
      value = !two_arguments ();
    }
  else if (STREQ (argv[pos], "(") && STREQ (argv[pos + 2], ")"))
    {
      advance (0);
      value = one_argument ();
      advance (0);
    }
  else if (STREQ (argv[pos + 1], "-a") || STREQ (argv[pos + 1], "-o"))
    value = expr ();
  else
    test_syntax_error (_("%s: binary operator expected\n"), argv[pos+1]);
  return (value);
}

/* This is an implementation of a Posix.2 proposal by David Korn. */
static int
posixtest (int nargs)
{
  int value;

  switch (nargs)
    {
      case 1:
	value = one_argument ();
	break;

      case 2:
	value = two_arguments ();
	break;

      case 3:
	value = three_arguments ();
	break;

      case 4:
	if (STREQ (argv[pos], "!"))
	  {
	    advance (1);
	    value = !three_arguments ();
	    break;
	  }
	if (STREQ (argv[pos], "(") && STREQ (argv[pos + 3], ")"))
	  {
	    advance (0);
	    value = two_arguments ();
	    advance (0);
	    break;
	  }
	/* FALLTHROUGH */
      case 5:
      default:
	if (nargs <= 0)
	  abort ();
	value = expr ();
    }

  return (value);
}

#if defined (TEST_STANDALONE)
# include "long-options.h"

void
usage (int status)
{
  if (status != 0)
    fprintf (stderr, _("Try `%s --help' for more information.\n"),
	     program_name);
  else
    {
      fputs (_("\
Usage: test EXPRESSION\n\
  or:  [ EXPRESSION ]\n\
  or:  [ OPTION\n\
Exit with the status determined by EXPRESSION.\n\
\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      fputs (_("\
\n\
EXPRESSION is true or false and sets exit status.  It is one of:\n\
"), stdout);
      fputs (_("\
\n\
  ( EXPRESSION )               EXPRESSION is true\n\
  ! EXPRESSION                 EXPRESSION is false\n\
  EXPRESSION1 -a EXPRESSION2   both EXPRESSION1 and EXPRESSION2 are true\n\
  EXPRESSION1 -o EXPRESSION2   either EXPRESSION1 or EXPRESSION2 is true\n\
"), stdout);
      fputs (_("\
\n\
  [-n] STRING          the length of STRING is nonzero\n\
  -z STRING            the length of STRING is zero\n\
  STRING1 = STRING2    the strings are equal\n\
  STRING1 != STRING2   the strings are not equal\n\
"), stdout);
      fputs (_("\
\n\
  INTEGER1 -eq INTEGER2   INTEGER1 is equal to INTEGER2\n\
  INTEGER1 -ge INTEGER2   INTEGER1 is greater than or equal to INTEGER2\n\
  INTEGER1 -gt INTEGER2   INTEGER1 is greater than INTEGER2\n\
  INTEGER1 -le INTEGER2   INTEGER1 is less than or equal to INTEGER2\n\
  INTEGER1 -lt INTEGER2   INTEGER1 is less than INTEGER2\n\
  INTEGER1 -ne INTEGER2   INTEGER1 is not equal to INTEGER2\n\
"), stdout);
      fputs (_("\
\n\
  FILE1 -ef FILE2   FILE1 and FILE2 have the same device and inode numbers\n\
  FILE1 -nt FILE2   FILE1 is newer (modification date) than FILE2\n\
  FILE1 -ot FILE2   FILE1 is older than FILE2\n\
"), stdout);
      fputs (_("\
\n\
  -b FILE     FILE exists and is block special\n\
  -c FILE     FILE exists and is character special\n\
  -d FILE     FILE exists and is a directory\n\
  -e FILE     FILE exists\n\
"), stdout);
      fputs (_("\
  -f FILE     FILE exists and is a regular file\n\
  -g FILE     FILE exists and is set-group-ID\n\
  -h FILE     FILE exists and is a symbolic link (same as -L)\n\
  -G FILE     FILE exists and is owned by the effective group ID\n\
  -k FILE     FILE exists and has its sticky bit set\n\
"), stdout);
      fputs (_("\
  -L FILE     FILE exists and is a symbolic link (same as -h)\n\
  -O FILE     FILE exists and is owned by the effective user ID\n\
  -p FILE     FILE exists and is a named pipe\n\
  -r FILE     FILE exists and is readable\n\
  -s FILE     FILE exists and has a size greater than zero\n\
"), stdout);
      fputs (_("\
  -S FILE     FILE exists and is a socket\n\
  -t [FD]     file descriptor FD (stdout by default) is opened on a terminal\n\
  -u FILE     FILE exists and its set-user-ID bit is set\n\
  -w FILE     FILE exists and is writable\n\
  -x FILE     FILE exists and is executable\n\
"), stdout);
      fputs (_("\
\n\
Beware that parentheses need to be escaped (e.g., by backslashes) for shells.\n\
INTEGER may also be -l STRING, which evaluates to the length of STRING.\n\
"), stdout);
      printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    }
  exit (status);
}
#endif /* TEST_STANDALONE */

#if !defined (TEST_STANDALONE)
# define main test_command
#endif

#define AUTHORS "Kevin Braunsdorf", "Matthew Bradburn"

/*
 * [:
 *	'[' expr ']'
 * test:
 *	test expr
 */
int
main (int margc, char **margv)
{
  int value;

#if !defined (TEST_STANDALONE)
  int code;

  code = setjmp (test_exit_buf);

  if (code)
    return (test_error_return);
#else /* TEST_STANDALONE */
  initialize_main (&margc, &margv);
  program_name = margv[0];
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  exit_failure = TEST_FAILURE;
  atexit (close_stdout);
#endif /* TEST_STANDALONE */

  argv = margv;

  if (LBRACKET)
    {
      /* Recognize --help or --version, but only when invoked in the
	 "[" form, and when the last argument is not "]".  POSIX
	 allows "[ --help" and "[ --version" to have the usual GNU
	 behavior, but it requires "test --help" and "test --version"
	 to exit silently with status 1.  */
      if (margc < 2 || strcmp (margv[margc - 1], "]") != 0)
	{
	  parse_long_options (margc, margv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
			      usage, AUTHORS, (char const *) NULL);
	  test_syntax_error (_("missing `]'\n"), NULL);
	}

      --margc;
    }

  argc = margc;
  pos = 1;

  if (pos >= argc)
    test_exit (SHELL_BOOLEAN (FALSE));

  value = posixtest (argc - 1);

  if (pos != argc)
    test_syntax_error (_("too many arguments\n"), NULL);

  test_exit (SHELL_BOOLEAN (value));
}