libiberty/argv.c

   1 /* Create and destroy argument vectors (argv's)
   2    Copyright (C) 1992, 2001 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
  39 #ifndef NULL
  40 #define NULL 0
  41 #endif
  42
  43 #ifndef EOS
  44 #define EOS '\0'
  45 #endif
  46
  47 #define INITIAL_MAXARGC 8       /* Number of args + NULL in initial argv */
  48
  49
  50 /*
  51
  52 @deftypefn Extension char** dupargv (char **@var{vector})
  53
  54 Duplicate an argument vector.  Simply scans through @var{vector},
  55 duplicating each argument until the terminating @code{NULL} is found.
  56 Returns a pointer to the argument vector if successful.  Returns
  57 @code{NULL} if there is insufficient memory to complete building the
  58 argument vector.
  59
  60 @end deftypefn
  61
  62 */
  63
  64 char **
  65 dupargv (char **argv)
  66 {
  67   int argc;
  68   char **copy;
  69
  70   if (argv == NULL)
  71     return NULL;
  72
  73   /* the vector */
  74   for (argc = 0; argv[argc] != NULL; argc++);
  75   copy = (char **) malloc ((argc + 1) * sizeof (char *));
  76   if (copy == NULL)
  77     return NULL;
  78
  79   /* the strings */
  80   for (argc = 0; argv[argc] != NULL; argc++)
  81     {
  82       int len = strlen (argv[argc]);
  83       copy[argc] = (char *) malloc (len + 1);
  84       if (copy[argc] == NULL)
  85         {
  86           freeargv (copy);
  87           return NULL;
  88         }
  89       strcpy (copy[argc], argv[argc]);
  90     }
  91   copy[argc] = NULL;
  92   return copy;
  93 }
  94
  95 /*
  96
  97 @deftypefn Extension void freeargv (char **@var{vector})
  98
  99 Free an argument vector that was built using @code{buildargv}.  Simply
 100 scans through @var{vector}, freeing the memory for each argument until
 101 the terminating @code{NULL} is found, and then frees @var{vector}
 102 itself.
 103
 104 @end deftypefn
 105
 106 */
 107
 108 void freeargv (char **vector)
 109 {
 110   register char **scan;
 111
 112   if (vector != NULL)
 113     {
 114       for (scan = vector; *scan != NULL; scan++)
 115         {
 116           free (*scan);
 117         }
 118       free (vector);
 119     }
 120 }
 121
 122 /*
 123
 124 @deftypefn Extension char** buildargv (char *@var{sp})
 125
 126 Given a pointer to a string, parse the string extracting fields
 127 separated by whitespace and optionally enclosed within either single
 128 or double quotes (which are stripped off), and build a vector of
 129 pointers to copies of the string for each field.  The input string
 130 remains unchanged.  The last element of the vector is followed by a
 131 @code{NULL} element.
 132
 133 All of the memory for the pointer array and copies of the string
 134 is obtained from @code{malloc}.  All of the memory can be returned to the
 135 system with the single function call @code{freeargv}, which takes the
 136 returned result of @code{buildargv}, as it's argument.
 137
 138 Returns a pointer to the argument vector if successful.  Returns
 139 @code{NULL} if @var{sp} is @code{NULL} or if there is insufficient
 140 memory to complete building the argument vector.
 141
 142 If the input is a null string (as opposed to a @code{NULL} pointer),
 143 then buildarg returns an argument vector that has one arg, a null
 144 string.
 145
 146 @end deftypefn
 147
 148 The memory for the argv array is dynamically expanded as necessary.
 149
 150 In order to provide a working buffer for extracting arguments into,
 151 with appropriate stripping of quotes and translation of backslash
 152 sequences, we allocate a working buffer at least as long as the input
 153 string.  This ensures that we always have enough space in which to
 154 work, since the extracted arg is never larger than the input string.
 155
 156 The argument vector is always kept terminated with a @code{NULL} arg
 157 pointer, so it can be passed to @code{freeargv} at any time, or
 158 returned, as appropriate.
 159
 160 */
 161
 162 char **buildargv (const char *input)
 163 {
 164   char *arg;
 165   char *copybuf;
 166   int squote = 0;
 167   int dquote = 0;
 168   int bsquote = 0;
 169   int argc = 0;
 170   int maxargc = 0;
 171   char **argv = NULL;
 172   char **nargv;
 173
 174   if (input != NULL)
 175     {
 176       copybuf = (char *) alloca (strlen (input) + 1);
 177       /* Is a do{}while to always execute the loop once.  Always return an
 178          argv, even for null strings.  See NOTES above, test case below. */
 179       do
 180         {
 181           /* Pick off argv[argc] */
 182           while (ISBLANK (*input))
 183             {
 184               input++;
 185             }
 186           if ((maxargc == 0) || (argc >= (maxargc - 1)))
 187             {
 188               /* argv needs initialization, or expansion */
 189               if (argv == NULL)
 190                 {
 191                   maxargc = INITIAL_MAXARGC;
 192                   nargv = (char **) malloc (maxargc * sizeof (char *));
 193                 }
 194               else
 195                 {
 196                   maxargc *= 2;
 197                   nargv = (char **) realloc (argv, maxargc * sizeof (char *));
 198                 }
 199               if (nargv == NULL)
 200                 {
 201                   if (argv != NULL)
 202                     {
 203                       freeargv (argv);
 204                       argv = NULL;
 205                     }
 206                   break;
 207                 }
 208               argv = nargv;
 209               argv[argc] = NULL;
 210             }
 211           /* Begin scanning arg */
 212           arg = copybuf;
 213           while (*input != EOS)
 214             {
 215               if (ISSPACE (*input) && !squote && !dquote && !bsquote)
 216                 {
 217                   break;
 218                 }
 219               else
 220                 {
 221                   if (bsquote)
 222                     {
 223                       bsquote = 0;
 224                       *arg++ = *input;
 225                     }
 226                   else if (*input == '\\')
 227                     {
 228                       bsquote = 1;
 229                     }
 230                   else if (squote)
 231                     {
 232                       if (*input == '\'')
 233                         {
 234                           squote = 0;
 235                         }
 236                       else
 237                         {
 238                           *arg++ = *input;
 239                         }
 240                     }
 241                   else if (dquote)
 242                     {
 243                       if (*input == '"')
 244                         {
 245                           dquote = 0;
 246                         }
 247                       else
 248                         {
 249                           *arg++ = *input;
 250                         }
 251                     }
 252                   else
 253                     {
 254                       if (*input == '\'')
 255                         {
 256                           squote = 1;
 257                         }
 258                       else if (*input == '"')
 259                         {
 260                           dquote = 1;
 261                         }
 262                       else
 263                         {
 264                           *arg++ = *input;
 265                         }
 266                     }
 267                   input++;
 268                 }
 269             }
 270           *arg = EOS;
 271           argv[argc] = strdup (copybuf);
 272           if (argv[argc] == NULL)
 273             {
 274               freeargv (argv);
 275               argv = NULL;
 276               break;
 277             }
 278           argc++;
 279           argv[argc] = NULL;
 280
 281           while (ISSPACE (*input))
 282             {
 283               input++;
 284             }
 285         }
 286       while (*input != EOS);
 287     }
 288   return (argv);
 289 }
 290
 291 /*
 292
 293 @deftypefn Extension void expandargv (int *@var{argcp}, char ***@var{argvp})
 294
 295 The @var{argcp} and @code{argvp} arguments are pointers to the usual
 296 @code{argc} and @code{argv} arguments to @code{main}.  This function
 297 looks for arguments that begin with the character @samp{@@}.  Any such
 298 arguments are interpreted as ``response files''.  The contents of the
 299 response file are interpreted as additional command line options.  In
 300 particular, the file is separated into whitespace-separated strings;
 301 each such string is taken as a command-line option.  The new options
 302 are inserted in place of the option naming the response file, and
 303 @code{*argcp} and @code{*argvp} will be updated.  If the value of
 304 @code{*argvp} is modified by this function, then the new value has
 305 been dynamically allocated and can be deallocated by the caller with
 306 @code{freeargv}.  However, most callers will simply call
 307 @code{expandargv} near the beginning of @code{main} and allow the
 308 operating system to free the memory when the program exits.
 309
 310 @end deftypefn
 311
 312 */
 313
 314 void
 315 expandargv (argcp, argvp)
 316      int *argcp;
 317      char ***argvp;
 318 {
 319   /* The argument we are currently processing.  */
 320   int i = 0;
 321   /* Non-zero if ***argvp has been dynamically allocated.  */
 322   int argv_dynamic = 0;
 323   /* Loop over the arguments, handling response files.  We always skip
 324      ARGVP[0], as that is the name of the program being run.  */
 325   while (++i < *argcp)
 326     {
 327       /* The name of the response file.  */
 328       const char *filename;
 329       /* The response file.  */
 330       FILE *f;
 331       /* The number of characters in the response file.  */
 332       long pos;
 333       /* A dynamically allocated buffer used to hold options read from a
 334          response file.  */
 335       char *buffer;
 336       /* Dynamically allocated storage for the options read from the
 337          response file.  */
 338       char **file_argv;
 339       /* The number of options read from the response file, if any.  */
 340      size_t file_argc;
 341       /* We are only interested in options of the form "@file".  */
 342       filename = (*argvp)[i];
 343       if (filename[0] != '@')
 344         continue;
 345       /* Read the contents of the file.  */
 346       f = fopen (++filename, "r");
 347       if (!f)
 348         continue;
 349       if (fseek (f, 0L, SEEK_END) == -1)
 350         goto error;
 351       pos = ftell (f);
 352       if (pos == -1)
 353         goto error;
 354       if (fseek (f, 0L, SEEK_SET) == -1)
 355         goto error;
 356       buffer = (char *) xmalloc (pos * sizeof (char) + 1);
 357       if (fread (buffer, sizeof (char), pos, f) != (size_t) pos)
 358         goto error;
 359       /* Add a NUL terminator.  */
 360       buffer[pos] = '\0';
 361       /* Parse the string.  */
 362       file_argv = buildargv (buffer);
 363       /* If *ARGVP is not already dynamically allocated, copy it.  */
 364       if (!argv_dynamic)
 365         {
 366           *argvp = dupargv (*argvp);
 367           if (!*argvp)
 368             /* We do not know exactly many bytes dupargv tried to
 369                allocate, so make a guess.  */
 370             xmalloc_failed (*argcp * 32);
 371         }
 372       /* Count the number of arguments.  */
 373       file_argc = 0;
 374       while (file_argv[file_argc] && *file_argv[file_argc])
 375         ++file_argc;
 376       /* Now, insert FILE_ARGV into ARGV.  The "+1" below handles the
 377          NULL terminator at the end of ARGV.  */
 378       *argvp = ((char **)
 379                 xrealloc (*argvp,
 380                           (*argcp + file_argc + 1) * sizeof (char *)));
 381       memmove (*argvp + i + file_argc, *argvp + i + 1,
 382                (*argcp - i) * sizeof (char *));
 383       memcpy (*argvp + i, file_argv, file_argc * sizeof (char *));
 384       /* The original option has been replaced by all the new
 385          options.  */
 386       *argcp += file_argc - 1;
 387       /* Free up memory allocated to process the response file.  We do
 388          not use freeargv because the individual options in FILE_ARGV
 389          are now in the main ARGV.  */
 390       free (file_argv);
 391       free (buffer);
 392       /* Rescan all of the arguments just read to support response
 393          files that include other response files.  */
 394       --i;
 395     error:
 396       /* We're all done with the file now.  */
 397       fclose (f);
 398     }
 399 }
 400
 401 #ifdef MAIN
 402
 403 /* Simple little test driver. */
 404
 405 static const char *const tests[] =
 406 {
 407   "a simple command line",
 408   "arg 'foo' is single quoted",
 409   "arg \"bar\" is double quoted",
 410   "arg \"foo bar\" has embedded whitespace",
 411   "arg 'Jack said \\'hi\\'' has single quotes",
 412   "arg 'Jack said \\\"hi\\\"' has double quotes",
 413   "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",
 414
 415   /* This should be expanded into only one argument.  */
 416   "trailing-whitespace ",
 417
 418   "",
 419   NULL
 420 };
 421
 422 int
 423 main (void)
 424 {
 425   char **argv;
 426   const char *const *test;
 427   char **targs;
 428
 429   for (test = tests; *test != NULL; test++)
 430     {
 431       printf ("buildargv(\"%s\")\n", *test);
 432       if ((argv = buildargv (*test)) == NULL)
 433         {
 434           printf ("failed!\n\n");
 435         }
 436       else
 437         {
 438           for (targs = argv; *targs != NULL; targs++)
 439             {
 440               printf ("\t\"%s\"\n", *targs);
 441             }
 442           printf ("\n");
 443         }
 444       freeargv (argv);
 445     }
 446
 447   return 0;
 448 }
 449
 450 #endif  /* MAIN */