1 /* Create and destroy argument vectors (argv's)
2 Copyright (C) 1992-2024 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 **
dupargv(char * const * argv)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
freeargv(char ** vector)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
consume_whitespace(const char ** input)119 consume_whitespace (const char **input)
120 {
121 while (ISSPACE (**input))
122 {
123 (*input)++;
124 }
125 }
126
127 static int
only_whitespace(const char * input)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
buildargv(const char * input)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 associated with FILE, separated by whitespace. Return 0 on success,
293 non-zero if an error occurred while writing to FILE.
294
295 @end deftypefn
296
297 */
298
299 int
writeargv(char * const * argv,FILE * f)300 writeargv (char * const *argv, FILE *f)
301 {
302 if (f == NULL)
303 return 1;
304
305 while (*argv != NULL)
306 {
307 const char *arg = *argv;
308
309 while (*arg != EOS)
310 {
311 char c = *arg;
312
313 if (ISSPACE(c) || c == '\\' || c == '\'' || c == '"')
314 if (EOF == fputc ('\\', f))
315 return 1;
316
317 if (EOF == fputc (c, f))
318 return 1;
319
320 arg++;
321 }
322
323 /* Write out a pair of quotes for an empty argument. */
324 if (arg == *argv)
325 if (EOF == fputs ("\"\"", f))
326 return 1;
327
328 if (EOF == fputc ('\n', f))
329 return 1;
330
331 argv++;
332 }
333
334 return 0;
335 }
336
337 /*
338
339 @deftypefn Extension void expandargv (int *@var{argcp}, char ***@var{argvp})
340
341 The @var{argcp} and @code{argvp} arguments are pointers to the usual
342 @code{argc} and @code{argv} arguments to @code{main}. This function
343 looks for arguments that begin with the character @samp{@@}. Any such
344 arguments are interpreted as ``response files''. The contents of the
345 response file are interpreted as additional command line options. In
346 particular, the file is separated into whitespace-separated strings;
347 each such string is taken as a command-line option. The new options
348 are inserted in place of the option naming the response file, and
349 @code{*argcp} and @code{*argvp} will be updated. If the value of
350 @code{*argvp} is modified by this function, then the new value has
351 been dynamically allocated and can be deallocated by the caller with
352 @code{freeargv}. However, most callers will simply call
353 @code{expandargv} near the beginning of @code{main} and allow the
354 operating system to free the memory when the program exits.
355
356 @end deftypefn
357
358 */
359
360 void
expandargv(int * argcp,char *** argvp)361 expandargv (int *argcp, char ***argvp)
362 {
363 /* The argument we are currently processing. */
364 int i = 0;
365 /* To check if ***argvp has been dynamically allocated. */
366 char ** const original_argv = *argvp;
367 /* Limit the number of response files that we parse in order
368 to prevent infinite recursion. */
369 unsigned int iteration_limit = 2000;
370 /* Loop over the arguments, handling response files. We always skip
371 ARGVP[0], as that is the name of the program being run. */
372 while (++i < *argcp)
373 {
374 /* The name of the response file. */
375 const char *filename;
376 /* The response file. */
377 FILE *f;
378 /* An upper bound on the number of characters in the response
379 file. */
380 long pos;
381 /* The number of characters in the response file, when actually
382 read. */
383 size_t len;
384 /* A dynamically allocated buffer used to hold options read from a
385 response file. */
386 char *buffer;
387 /* Dynamically allocated storage for the options read from the
388 response file. */
389 char **file_argv;
390 /* The number of options read from the response file, if any. */
391 size_t file_argc;
392 #ifdef S_ISDIR
393 struct stat sb;
394 #endif
395 /* We are only interested in options of the form "@file". */
396 filename = (*argvp)[i];
397 if (filename[0] != '@')
398 continue;
399 /* If we have iterated too many times then stop. */
400 if (-- iteration_limit == 0)
401 {
402 fprintf (stderr, "%s: error: too many @-files encountered\n", (*argvp)[0]);
403 xexit (1);
404 }
405 #ifdef S_ISDIR
406 if (stat (filename+1, &sb) < 0)
407 continue;
408 if (S_ISDIR(sb.st_mode))
409 {
410 fprintf (stderr, "%s: error: @-file refers to a directory\n", (*argvp)[0]);
411 xexit (1);
412 }
413 #endif
414 /* Read the contents of the file. */
415 f = fopen (++filename, "r");
416 if (!f)
417 continue;
418 if (fseek (f, 0L, SEEK_END) == -1)
419 goto error;
420 pos = ftell (f);
421 if (pos == -1)
422 goto error;
423 if (fseek (f, 0L, SEEK_SET) == -1)
424 goto error;
425 buffer = (char *) xmalloc (pos * sizeof (char) + 1);
426 len = fread (buffer, sizeof (char), pos, f);
427 if (len != (size_t) pos
428 /* On Windows, fread may return a value smaller than POS,
429 due to CR/LF->CR translation when reading text files.
430 That does not in-and-of itself indicate failure. */
431 && ferror (f))
432 {
433 free (buffer);
434 goto error;
435 }
436 /* Add a NUL terminator. */
437 buffer[len] = '\0';
438 /* If the file is empty or contains only whitespace, buildargv would
439 return a single empty argument. In this context we want no arguments,
440 instead. */
441 if (only_whitespace (buffer))
442 {
443 file_argv = (char **) xmalloc (sizeof (char *));
444 file_argv[0] = NULL;
445 }
446 else
447 /* Parse the string. */
448 file_argv = buildargv (buffer);
449 /* If *ARGVP is not already dynamically allocated, copy it. */
450 if (*argvp == original_argv)
451 *argvp = dupargv (*argvp);
452 /* Count the number of arguments. */
453 file_argc = 0;
454 while (file_argv[file_argc])
455 ++file_argc;
456 /* Free the original option's memory. */
457 free ((*argvp)[i]);
458 /* Now, insert FILE_ARGV into ARGV. The "+1" below handles the
459 NULL terminator at the end of ARGV. */
460 *argvp = ((char **)
461 xrealloc (*argvp,
462 (*argcp + file_argc + 1) * sizeof (char *)));
463 memmove (*argvp + i + file_argc, *argvp + i + 1,
464 (*argcp - i) * sizeof (char *));
465 memcpy (*argvp + i, file_argv, file_argc * sizeof (char *));
466 /* The original option has been replaced by all the new
467 options. */
468 *argcp += file_argc - 1;
469 /* Free up memory allocated to process the response file. We do
470 not use freeargv because the individual options in FILE_ARGV
471 are now in the main ARGV. */
472 free (file_argv);
473 free (buffer);
474 /* Rescan all of the arguments just read to support response
475 files that include other response files. */
476 --i;
477 error:
478 /* We're all done with the file now. */
479 fclose (f);
480 }
481 }
482
483 /*
484
485 @deftypefn Extension int countargv (char * const *@var{argv})
486
487 Return the number of elements in @var{argv}.
488 Returns zero if @var{argv} is NULL.
489
490 @end deftypefn
491
492 */
493
494 int
countargv(char * const * argv)495 countargv (char * const *argv)
496 {
497 int argc;
498
499 if (argv == NULL)
500 return 0;
501 for (argc = 0; argv[argc] != NULL; argc++)
502 continue;
503 return argc;
504 }
505
506 #ifdef MAIN
507
508 /* Simple little test driver. */
509
510 static const char *const tests[] =
511 {
512 "a simple command line",
513 "arg 'foo' is single quoted",
514 "arg \"bar\" is double quoted",
515 "arg \"foo bar\" has embedded whitespace",
516 "arg 'Jack said \\'hi\\'' has single quotes",
517 "arg 'Jack said \\\"hi\\\"' has double quotes",
518 "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",
519
520 /* This should be expanded into only one argument. */
521 "trailing-whitespace ",
522
523 "",
524 NULL
525 };
526
527 int
main(void)528 main (void)
529 {
530 char **argv;
531 const char *const *test;
532 char **targs;
533
534 for (test = tests; *test != NULL; test++)
535 {
536 printf ("buildargv(\"%s\")\n", *test);
537 if ((argv = buildargv (*test)) == NULL)
538 {
539 printf ("failed!\n\n");
540 }
541 else
542 {
543 for (targs = argv; *targs != NULL; targs++)
544 {
545 printf ("\t\"%s\"\n", *targs);
546 }
547 printf ("\n");
548 }
549 freeargv (argv);
550 }
551
552 return 0;
553 }
554
555 #endif /* MAIN */
556