aboutsummaryrefslogtreecommitdiff
path: root/libiberty/argv.c
blob: 8c9794db6a211ba5b46f55fa52048633ba8350fa (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
/* Create and destroy argument vectors (argv's)
   Copyright (C) 1992-2020 Free Software Foundation, Inc.
   Written by Fred Fish @ Cygnus Support

This file is part of the libiberty library.
Libiberty is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

Libiberty 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with libiberty; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
Boston, MA 02110-1301, USA.  */


/*  Create and destroy argument vectors.  An argument vector is simply an
    array of string pointers, terminated by a NULL pointer. */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "ansidecl.h"
#include "libiberty.h"
#include "safe-ctype.h"

/*  Routines imported from standard C runtime libraries. */

#include <stddef.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif

#ifndef NULL
#define NULL 0
#endif

#ifndef EOS
#define EOS '\0'
#endif

#define INITIAL_MAXARGC 8	/* Number of args + NULL in initial argv */


/*

@deftypefn Extension char** dupargv (char * const *@var{vector})

Duplicate an argument vector.  Simply scans through @var{vector},
duplicating each argument until the terminating @code{NULL} is found.
Returns a pointer to the argument vector if successful.  Returns
@code{NULL} if there is insufficient memory to complete building the
argument vector.

@end deftypefn

*/

char **
dupargv (char * const *argv)
{
  int argc;
  char **copy;
  
  if (argv == NULL)
    return NULL;
  
  /* the vector */
  for (argc = 0; argv[argc] != NULL; argc++);
  copy = (char **) xmalloc ((argc + 1) * sizeof (char *));

  /* the strings */
  for (argc = 0; argv[argc] != NULL; argc++)
    copy[argc] = xstrdup (argv[argc]);
  copy[argc] = NULL;
  return copy;
}

/*

@deftypefn Extension void freeargv (char **@var{vector})

Free an argument vector that was built using @code{buildargv}.  Simply
scans through @var{vector}, freeing the memory for each argument until
the terminating @code{NULL} is found, and then frees @var{vector}
itself.

@end deftypefn

*/

void freeargv (char **vector)
{
  register char **scan;

  if (vector != NULL)
    {
      for (scan = vector; *scan != NULL; scan++)
	{
	  free (*scan);
	}
      free (vector);
    }
}

static void
consume_whitespace (const char **input)
{
  while (ISSPACE (**input))
    {
      (*input)++;
    }
}

static int
only_whitespace (const char* input)
{
  while (*input != EOS && ISSPACE (*input))
    input++;

  return (*input == EOS);
}

/*

@deftypefn Extension char** buildargv (char *@var{sp})

Given a pointer to a string, parse the string extracting fields
separated by whitespace and optionally enclosed within either single
or double quotes (which are stripped off), and build a vector of
pointers to copies of the string for each field.  The input string
remains unchanged.  The last element of the vector is followed by a
@code{NULL} element.

All of the memory for the pointer array and copies of the string
is obtained from @code{xmalloc}.  All of the memory can be returned to the
system with the single function call @code{freeargv}, which takes the
returned result of @code{buildargv}, as it's argument.

Returns a pointer to the argument vector if successful.  Returns
@code{NULL} if @var{sp} is @code{NULL} or if there is insufficient
memory to complete building the argument vector.

If the input is a null string (as opposed to a @code{NULL} pointer),
then buildarg returns an argument vector that has one arg, a null
string.

@end deftypefn

The memory for the argv array is dynamically expanded as necessary.

In order to provide a working buffer for extracting arguments into,
with appropriate stripping of quotes and translation of backslash
sequences, we allocate a working buffer at least as long as the input
string.  This ensures that we always have enough space in which to
work, since the extracted arg is never larger than the input string.

The argument vector is always kept terminated with a @code{NULL} arg
pointer, so it can be passed to @code{freeargv} at any time, or
returned, as appropriate.

*/

char **buildargv (const char *input)
{
  char *arg;
  char *copybuf;
  int squote = 0;
  int dquote = 0;
  int bsquote = 0;
  int argc = 0;
  int maxargc = 0;
  char **argv = NULL;
  char **nargv;

  if (input != NULL)
    {
      copybuf = (char *) xmalloc (strlen (input) + 1);
      /* Is a do{}while to always execute the loop once.  Always return an
	 argv, even for null strings.  See NOTES above, test case below. */
      do
	{
	  /* Pick off argv[argc] */
	  consume_whitespace (&input);

	  if ((maxargc == 0) || (argc >= (maxargc - 1)))
	    {
	      /* argv needs initialization, or expansion */
	      if (argv == NULL)
		{
		  maxargc = INITIAL_MAXARGC;
		  nargv = (char **) xmalloc (maxargc * sizeof (char *));
		}
	      else
		{
		  maxargc *= 2;
		  nargv = (char **) xrealloc (argv, maxargc * sizeof (char *));
		}
	      argv = nargv;
	      argv[argc] = NULL;
	    }
	  /* Begin scanning arg */
	  arg = copybuf;
	  while (*input != EOS)
	    {
	      if (ISSPACE (*input) && !squote && !dquote && !bsquote)
		{
		  break;
		}
	      else
		{
		  if (bsquote)
		    {
		      bsquote = 0;
		      *arg++ = *input;
		    }
		  else if (*input == '\\')
		    {
		      bsquote = 1;
		    }
		  else if (squote)
		    {
		      if (*input == '\'')
			{
			  squote = 0;
			}
		      else
			{
			  *arg++ = *input;
			}
		    }
		  else if (dquote)
		    {
		      if (*input == '"')
			{
			  dquote = 0;
			}
		      else
			{
			  *arg++ = *input;
			}
		    }
		  else
		    {
		      if (*input == '\'')
			{
			  squote = 1;
			}
		      else if (*input == '"')
			{
			  dquote = 1;
			}
		      else
			{
			  *arg++ = *input;
			}
		    }
		  input++;
		}
	    }
	  *arg = EOS;
	  argv[argc] = xstrdup (copybuf);
	  argc++;
	  argv[argc] = NULL;

	  consume_whitespace (&input);
	}
      while (*input != EOS);

      free (copybuf);
    }
  return (argv);
}

/*

@deftypefn Extension int writeargv (char * const *@var{argv}, FILE *@var{file})

Write each member of ARGV, handling all necessary quoting, to the file
named by FILE, separated by whitespace.  Return 0 on success, non-zero
if an error occurred while writing to FILE.

@end deftypefn

*/

int
writeargv (char * const *argv, FILE *f)
{
  int status = 0;

  if (f == NULL)
    return 1;

  while (*argv != NULL)
    {
      const char *arg = *argv;

      while (*arg != EOS)
        {
          char c = *arg;

          if (ISSPACE(c) || c == '\\' || c == '\'' || c == '"')
            if (EOF == fputc ('\\', f))
              {
                status = 1;
                goto done;
              }

          if (EOF == fputc (c, f))
            {
              status = 1;
              goto done;
            }
          arg++;
        }

      if (EOF == fputc ('\n', f))
        {
          status = 1;
          goto done;
        }
      argv++;
    }

 done:
  return status;
}

/*

@deftypefn Extension void expandargv (int *@var{argcp}, char ***@var{argvp})

The @var{argcp} and @code{argvp} arguments are pointers to the usual
@code{argc} and @code{argv} arguments to @code{main}.  This function
looks for arguments that begin with the character @samp{@@}.  Any such
arguments are interpreted as ``response files''.  The contents of the
response file are interpreted as additional command line options.  In
particular, the file is separated into whitespace-separated strings;
each such string is taken as a command-line option.  The new options
are inserted in place of the option naming the response file, and
@code{*argcp} and @code{*argvp} will be updated.  If the value of
@code{*argvp} is modified by this function, then the new value has
been dynamically allocated and can be deallocated by the caller with
@code{freeargv}.  However, most callers will simply call
@code{expandargv} near the beginning of @code{main} and allow the
operating system to free the memory when the program exits.

@end deftypefn

*/

void
expandargv (int *argcp, char ***argvp)
{
  /* The argument we are currently processing.  */
  int i = 0;
  /* To check if ***argvp has been dynamically allocated.  */
  char ** const original_argv = *argvp;
  /* Limit the number of response files that we parse in order
     to prevent infinite recursion.  */
  unsigned int iteration_limit = 2000;
  /* Loop over the arguments, handling response files.  We always skip
     ARGVP[0], as that is the name of the program being run.  */
  while (++i < *argcp)
    {
      /* The name of the response file.  */
      const char *filename;
      /* The response file.  */
      FILE *f;
      /* An upper bound on the number of characters in the response
	 file.  */
      long pos;
      /* The number of characters in the response file, when actually
	 read.  */
      size_t len;
      /* A dynamically allocated buffer used to hold options read from a
	 response file.  */
      char *buffer;
      /* Dynamically allocated storage for the options read from the
	 response file.  */
      char **file_argv;
      /* The number of options read from the response file, if any.  */
      size_t file_argc;
#ifdef S_ISDIR
      struct stat sb;
#endif
      /* We are only interested in options of the form "@file".  */
      filename = (*argvp)[i];
      if (filename[0] != '@')
	continue;
      /* If we have iterated too many times then stop.  */
      if (-- iteration_limit == 0)
	{
	  fprintf (stderr, "%s: error: too many @-files encountered\n", (*argvp)[0]);
	  xexit (1);
	}
#ifdef S_ISDIR
      if (stat (filename+1, &sb) < 0)
	continue;
      if (S_ISDIR(sb.st_mode))
	{
	  fprintf (stderr, "%s: error: @-file refers to a directory\n", (*argvp)[0]);
	  xexit (1);
	}
#endif
      /* Read the contents of the file.  */
      f = fopen (++filename, "r");
      if (!f)
	continue;
      if (fseek (f, 0L, SEEK_END) == -1)
	goto error;
      pos = ftell (f);
      if (pos == -1)
	goto error;
      if (fseek (f, 0L, SEEK_SET) == -1)
	goto error;
      buffer = (char *) xmalloc (pos * sizeof (char) + 1);
      len = fread (buffer, sizeof (char), pos, f);
      if (len != (size_t) pos
	  /* On Windows, fread may return a value smaller than POS,
	     due to CR/LF->CR translation when reading text files.
	     That does not in-and-of itself indicate failure.  */
	  && ferror (f))
	goto error;
      /* Add a NUL terminator.  */
      buffer[len] = '\0';
      /* If the file is empty or contains only whitespace, buildargv would
	 return a single empty argument.  In this context we want no arguments,
	 instead.  */
      if (only_whitespace (buffer))
	{
	  file_argv = (char **) xmalloc (sizeof (char *));
	  file_argv[0] = NULL;
	}
      else
	/* Parse the string.  */
	file_argv = buildargv (buffer);
      /* If *ARGVP is not already dynamically allocated, copy it.  */
      if (*argvp == original_argv)
	*argvp = dupargv (*argvp);
      /* Count the number of arguments.  */
      file_argc = 0;
      while (file_argv[file_argc])
	++file_argc;
      /* Free the original option's memory.  */
      free ((*argvp)[i]);
      /* Now, insert FILE_ARGV into ARGV.  The "+1" below handles the
	 NULL terminator at the end of ARGV.  */ 
      *argvp = ((char **) 
		xrealloc (*argvp, 
			  (*argcp + file_argc + 1) * sizeof (char *)));
      memmove (*argvp + i + file_argc, *argvp + i + 1, 
	       (*argcp - i) * sizeof (char *));
      memcpy (*argvp + i, file_argv, file_argc * sizeof (char *));
      /* The original option has been replaced by all the new
	 options.  */
      *argcp += file_argc - 1;
      /* Free up memory allocated to process the response file.  We do
	 not use freeargv because the individual options in FILE_ARGV
	 are now in the main ARGV.  */
      free (file_argv);
      free (buffer);
      /* Rescan all of the arguments just read to support response
	 files that include other response files.  */
      --i;
    error:
      /* We're all done with the file now.  */
      fclose (f);
    }
}

/*

@deftypefn Extension int countargv (char * const *@var{argv})

Return the number of elements in @var{argv}.
Returns zero if @var{argv} is NULL.

@end deftypefn

*/

int
countargv (char * const *argv)
{
  int argc;

  if (argv == NULL)
    return 0;
  for (argc = 0; argv[argc] != NULL; argc++)
    continue;
  return argc;
}

#ifdef MAIN

/* Simple little test driver. */

static const char *const tests[] =
{
  "a simple command line",
  "arg 'foo' is single quoted",
  "arg \"bar\" is double quoted",
  "arg \"foo bar\" has embedded whitespace",
  "arg 'Jack said \\'hi\\'' has single quotes",
  "arg 'Jack said \\\"hi\\\"' has double quotes",
  "a b c d e f g h i j k l m n o p q r s t u v w x y z 1 2 3 4 5 6 7 8 9",
  
  /* This should be expanded into only one argument.  */
  "trailing-whitespace ",

  "",
  NULL
};

int
main (void)
{
  char **argv;
  const char *const *test;
  char **targs;

  for (test = tests; *test != NULL; test++)
    {
      printf ("buildargv(\"%s\")\n", *test);
      if ((argv = buildargv (*test)) == NULL)
	{
	  printf ("failed!\n\n");
	}
      else
	{
	  for (targs = argv; *targs != NULL; targs++)
	    {
	      printf ("\t\"%s\"\n", *targs);
	    }
	  printf ("\n");
	}
      freeargv (argv);
    }

  return 0;
}

#endif	/* MAIN */