1 /* Create and destroy argument vectors (argv's)
2 Copyright (C) 1992-2023 Free Software Foundation, Inc.
3 Written by Fred Fish @ Cygnus Support
4
5 This file is part of the libiberty library.
6 Libiberty is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public
8 License as published by the Free Software Foundation; either
9 version 2 of the License, or (at your option) any later version.
10
11 Libiberty is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Library General Public License for more details.
15
16 You should have received a copy of the GNU Library General Public
17 License along with libiberty; see the file COPYING.LIB. If
18 not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
19 Boston, MA 02110-1301, USA. */
20
21
22 /* Create and destroy argument vectors. An argument vector is simply an
23 array of string pointers, terminated by a NULL pointer. */
24
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28 #include "ansidecl.h"
29 #include "libiberty.h"
30 #include "safe-ctype.h"
31
32 /* Routines imported from standard C runtime libraries. */
33
34 #include <stddef.h>
35 #include <string.h>
36 #include <stdlib.h>
37 #include <stdio.h>
38 #include <sys/types.h>
39 #ifdef HAVE_UNISTD_H
40 #include <unistd.h>
41 #endif
42 #if HAVE_SYS_STAT_H
43 #include <sys/stat.h>
44 #endif
45
46 #ifndef NULL
47 #define NULL 0
48 #endif
49
50 #ifndef EOS
51 #define EOS '\0'
52 #endif
53
54 #define INITIAL_MAXARGC 8 /* Number of args + NULL in initial argv */
55
56
57 /*
58
59 @deftypefn Extension char** dupargv (char * const *@var{vector})
60
61 Duplicate an argument vector. Simply scans through @var{vector},
62 duplicating each argument until the terminating @code{NULL} is found.
63 Returns a pointer to the argument vector if successful. Returns
64 @code{NULL} if there is insufficient memory to complete building the
65 argument vector.
66
67 @end deftypefn
68
69 */
70
71 char **
72 dupargv (char * const *argv)
73 {
74 int argc;
75 char **copy;
76
77 if (argv == NULL)
78 return NULL;
79
80 /* the vector */
81 for (argc = 0; argv[argc] != NULL; argc++);
82 copy = (char **) xmalloc ((argc + 1) * sizeof (char *));
83
84 /* the strings */
85 for (argc = 0; argv[argc] != NULL; argc++)
86 copy[argc] = xstrdup (argv[argc]);
87 copy[argc] = NULL;
88 return copy;
89 }
90
91 /*
92
93 @deftypefn Extension void freeargv (char **@var{vector})
94
95 Free an argument vector that was built using @code{buildargv}. Simply
96 scans through @var{vector}, freeing the memory for each argument until
97 the terminating @code{NULL} is found, and then frees @var{vector}
98 itself.
99
100 @end deftypefn
101
102 */
103
104 void freeargv (char **vector)
105 {
106 register char **scan;
107
108 if (vector != NULL)
109 {
110 for (scan = vector; *scan != NULL; scan++)
111 {
112 free (*scan);
113 }
114 free (vector);
115 }
116 }
117
118 static void
119 consume_whitespace (const char **input)
120 {
121 while (ISSPACE (**input))
122 {
123 (*input)++;
124 }
125 }
126
127 static int
128 only_whitespace (const char* input)
129 {
130 while (*input != EOS && ISSPACE (*input))
131 input++;
132
133 return (*input == EOS);
134 }
135
136 /*
137
138 @deftypefn Extension char** buildargv (char *@var{sp})
139
140 Given a pointer to a string, parse the string extracting fields
141 separated by whitespace and optionally enclosed within either single
142 or double quotes (which are stripped off), and build a vector of
143 pointers to copies of the string for each field. The input string
144 remains unchanged. The last element of the vector is followed by a
145 @code{NULL} element.
146
147 All of the memory for the pointer array and copies of the string
148 is obtained from @code{xmalloc}. All of the memory can be returned to the
149 system with the single function call @code{freeargv}, which takes the
150 returned result of @code{buildargv}, as it's argument.
151
152 Returns a pointer to the argument vector if successful. Returns
153 @code{NULL} if @var{sp} is @code{NULL} or if there is insufficient
154 memory to complete building the argument vector.
155
156 If the input is a null string (as opposed to a @code{NULL} pointer),
157 then buildarg returns an argument vector that has one arg, a null
158 string.
159
160 @end deftypefn
161
162 The memory for the argv array is dynamically expanded as necessary.
163
164 In order to provide a working buffer for extracting arguments into,
165 with appropriate stripping of quotes and translation of backslash
166 sequences, we allocate a working buffer at least as long as the input
167 string. This ensures that we always have enough space in which to
168 work, since the extracted arg is never larger than the input string.
169
170 The argument vector is always kept terminated with a @code{NULL} arg
171 pointer, so it can be passed to @code{freeargv} at any time, or
172 returned, as appropriate.
173
174 */
175
176 char **buildargv (const char *input)
177 {
178 char *arg;
179 char *copybuf;
180 int squote = 0;
181 int dquote = 0;
182 int bsquote = 0;
183 int argc = 0;
184 int maxargc = 0;
185 char **argv = NULL;
186 char **nargv;
187
188 if (input != NULL)
189 {
190 copybuf = (char *) xmalloc (strlen (input) + 1);
191 /* Is a do{}while to always execute the loop once. Always return an
192 argv, even for null strings. See NOTES above, test case below. */
193 do
194 {
195 /* Pick off argv[argc] */
196 consume_whitespace (&input);
197
198 if ((maxargc == 0) || (argc >= (maxargc - 1)))
199 {
200 /* argv needs initialization, or expansion */
201 if (argv == NULL)
202 {
203 maxargc = INITIAL_MAXARGC;
204 nargv = (char **) xmalloc (maxargc * sizeof (char *));
205 }
206 else
207 {
208 maxargc *= 2;
209 nargv = (char **) xrealloc (argv, maxargc * sizeof (char *));
210 }
211 argv = nargv;
212 argv[argc] = NULL;
213 }
214 /* Begin scanning arg */
215 arg = copybuf;
216 while (*input != EOS)
217 {
218 if (ISSPACE (*input) && !squote && !dquote && !bsquote)
219 {
220 break;
221 }
222 else
223 {
224 if (bsquote)
225 {
226 bsquote = 0;
227 *arg++ = *input;
228 }
229 else if (*input == '\\')
230 {
231 bsquote = 1;
232 }
233 else if (squote)
234 {
235 if (*input == '\'')
236 {
237 squote = 0;
238 }
239 else
240 {
241 *arg++ = *input;
242 }
243 }
244 else if (dquote)
245 {
246 if (*input == '"')
247 {
248 dquote = 0;
249 }
250 else
251 {
252 *arg++ = *input;
253 }
254 }
255 else
256 {
257 if (*input == '\'')
258 {
259 squote = 1;
260 }
261 else if (*input == '"')
262 {
263 dquote = 1;
264 }
265 else
266 {
267 *arg++ = *input;
268 }
269 }
270 input++;
271 }
272 }
273 *arg = EOS;
274 argv[argc] = xstrdup (copybuf);
275 argc++;
276 argv[argc] = NULL;
277
278 consume_whitespace (&input);
279 }
280 while (*input != EOS);
281
282 free (copybuf);
283 }
284 return (argv);
285 }
286
287 /*
288
289 @deftypefn Extension int writeargv (char * const *@var{argv}, FILE *@var{file})
290
291 Write each member of ARGV, handling all necessary quoting, to the file
292 named by FILE, separated by whitespace. Return 0 on success, non-zero
293 if an error occurred while writing to FILE.
294
295 @end deftypefn
296
297 */
298
299 int
300 writeargv (char * const *argv, FILE *f)
301 {
302 int status = 0;
303
304 if (f == NULL)
305 return 1;
306
307 while (*argv != NULL)
308 {
309 const char *arg = *argv;
310
311 while (*arg != EOS)
312 {
313 char c = *arg;
314
315 if (ISSPACE(c) || c == '\\' || c == '\'' || c == '"')
316 if (EOF == fputc ('\\', f))
317 {
318 status = 1;
319 goto done;
320 }
321
322 if (EOF == fputc (c, f))
323 {
324 status = 1;
325 goto done;
326 }
327 arg++;
328 }
329
330 /* Write out a pair of quotes for an empty argument. */
331 if (arg == *argv)
332 if (EOF == fputs ("\"\"", f))
333 {
334 status = 1;
335 goto done;
336 }
337
338 if (EOF == fputc ('\n', f))
339 {
340 status = 1;
341 goto done;
342 }
343 argv++;
344 }
345
346 done:
347 return status;
348 }
349
350 /*
351
352 @deftypefn Extension void expandargv (int *@var{argcp}, char ***@var{argvp})
353
354 The @var{argcp} and @code{argvp} arguments are pointers to the usual
355 @code{argc} and @code{argv} arguments to @code{main}. This function
356 looks for arguments that begin with the character @samp{@@}. Any such
357 arguments are interpreted as ``response files''. The contents of the
358 response file are interpreted as additional command line options. In
359 particular, the file is separated into whitespace-separated strings;
360 each such string is taken as a command-line option. The new options
361 are inserted in place of the option naming the response file, and
362 @code{*argcp} and @code{*argvp} will be updated. If the value of
363 @code{*argvp} is modified by this function, then the new value has
364 been dynamically allocated and can be deallocated by the caller with
365 @code{freeargv}. However, most callers will simply call
366 @code{expandargv} near the beginning of @code{main} and allow the
367 operating system to free the memory when the program exits.
368
369 @end deftypefn
370
371 */
372
373 void
374 expandargv (int *argcp, char ***argvp)
375 {
376 /* The argument we are currently processing. */
377 int i = 0;
378 /* To check if ***argvp has been dynamically allocated. */
379 char ** const original_argv = *argvp;
380 /* Limit the number of response files that we parse in order
381 to prevent infinite recursion. */
382 unsigned int iteration_limit = 2000;
383 /* Loop over the arguments, handling response files. We always skip
384 ARGVP[0], as that is the name of the program being run. */
385 while (++i < *argcp)
386 {
387 /* The name of the response file. */
388 const char *filename;
389 /* The response file. */
390 FILE *f;
391 /* An upper bound on the number of characters in the response
392 file. */
393 long pos;
394 /* The number of characters in the response file, when actually
395 read. */
396 size_t len;
397 /* A dynamically allocated buffer used to hold options read from a
398 response file. */
399 char *buffer;
400 /* Dynamically allocated storage for the options read from the
401 response file. */
402 char **file_argv;
403 /* The number of options read from the response file, if any. */
404 size_t file_argc;
405 #ifdef S_ISDIR
406 struct stat sb;
407 #endif
408 /* We are only interested in options of the form "@file". */
409 filename = (*argvp)[i];
410 if (filename[0] != '@')
411 continue;
412 /* If we have iterated too many times then stop. */
413 if (-- iteration_limit == 0)
414 {
415 fprintf (stderr, "%s: error: too many @-files encountered\n", (*argvp)[0]);
416 xexit (1);
417 }
418 #ifdef S_ISDIR
419 if (stat (filename+1, &sb) < 0)
420 continue;
421 if (S_ISDIR(sb.st_mode))
422 {
423 fprintf (stderr, "%s: error: @-file refers to a directory\n", (*argvp)[0]);
424 xexit (1);
425 }
426 #endif
427 /* Read the contents of the file. */
428 f = fopen (++filename, "r");
429 if (!f)
430 continue;
431 if (fseek (f, 0L, SEEK_END) == -1)
432 goto error;
433 pos = ftell (f);
434 if (pos == -1)
435 goto error;
436 if (fseek (f, 0L, SEEK_SET) == -1)
437 goto error;
438 buffer = (char *) xmalloc (pos * sizeof (char) + 1);
439 len = fread (buffer, sizeof (char), pos, f);
440 if (len != (size_t) pos
441 /* On Windows, fread may return a value smaller than POS,
442 due to CR/LF->CR translation when reading text files.
443 That does not in-and-of itself indicate failure. */
444 && ferror (f))
445 {
446 free (buffer);
447 goto error;
448 }
449 /* Add a NUL terminator. */
450 buffer[len] = '\0';
451 /* If the file is empty or contains only whitespace, buildargv would
452 return a single empty argument. In this context we want no arguments,
453 instead. */
454 if (only_whitespace (buffer))
455 {
456 file_argv = (char **) xmalloc (sizeof (char *));
457 file_argv[0] = NULL;
458 }
459 else
460 /* Parse the string. */
461 file_argv = buildargv (buffer);
462 /* If *ARGVP is not already dynamically allocated, copy it. */
463 if (*argvp == original_argv)
464 *argvp = dupargv (*argvp);
465 /* Count the number of arguments. */
466 file_argc = 0;
467 while (file_argv[file_argc])
468 ++file_argc;
469 /* Free the original option's memory. */
470 free ((*argvp)[i]);
471 /* Now, insert FILE_ARGV into ARGV. The "+1" below handles the
472 NULL terminator at the end of ARGV. */
473 *argvp = ((char **)
474 xrealloc (*argvp,
475 (*argcp + file_argc + 1) * sizeof (char *)));
476 memmove (*argvp + i + file_argc, *argvp + i + 1,
477 (*argcp - i) * sizeof (char *));
478 memcpy (*argvp + i, file_argv, file_argc * sizeof (char *));
479 /* The original option has been replaced by all the new
480 options. */
481 *argcp += file_argc - 1;
482 /* Free up memory allocated to process the response file. We do
483 not use freeargv because the individual options in FILE_ARGV
484 are now in the main ARGV. */
485 free (file_argv);
486 free (buffer);
487 /* Rescan all of the arguments just read to support response
488 files that include other response files. */
489 --i;
490 error:
491 /* We're all done with the file now. */
492 fclose (f);
493 }
494 }
495
496 /*
497
498 @deftypefn Extension int countargv (char * const *@var{argv})
499
500 Return the number of elements in @var{argv}.
501 Returns zero if @var{argv} is NULL.
502
503 @end deftypefn
504
505 */
506
507 int
508 countargv (char * const *argv)
509 {
510 int argc;
511
512 if (argv == NULL)
513 return 0;
514 for (argc = 0; argv[argc] != NULL; argc++)
515 continue;
516 return argc;
517 }
518
519 #ifdef MAIN
520
521 /* Simple little test driver. */
522
523 static const char *const tests[] =
524 {
525 "a simple command line",
526 "arg 'foo' is single quoted",
527 "arg \"bar\" is double quoted",
528 "arg \"foo bar\" has embedded whitespace",
529 "arg 'Jack said \\'hi\\'' has single quotes",
530 "arg 'Jack said \\\"hi\\\"' has double quotes",
531 "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",
532
533 /* This should be expanded into only one argument. */
534 "trailing-whitespace ",
535
536 "",
537 NULL
538 };
539
540 int
541 main (void)
542 {
543 char **argv;
544 const char *const *test;
545 char **targs;
546
547 for (test = tests; *test != NULL; test++)
548 {
549 printf ("buildargv(\"%s\")\n", *test);
550 if ((argv = buildargv (*test)) == NULL)
551 {
552 printf ("failed!\n\n");
553 }
554 else
555 {
556 for (targs = argv; *targs != NULL; targs++)
557 {
558 printf ("\t\"%s\"\n", *targs);
559 }
560 printf ("\n");
561 }
562 freeargv (argv);
563 }
564
565 return 0;
566 }
567
568 #endif /* MAIN */