libiberty/argv.c

   1 /* Create and destroy argument vectors (argv's)
   2    Copyright (C) 1992 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., 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, 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 #include "ansidecl.h"
  26 #include "libiberty.h"
  27
  28 #ifdef isspace
  29 #undef isspace
  30 #endif
  31 #define isspace(ch) ((ch) == ' ' || (ch) == '\t')
  32
  33 /*  Routines imported from standard C runtime libraries. */
  34
  35 #ifdef __STDC__
  36
  37 #include <stddef.h>
  38 extern void *memcpy (void *s1, const void *s2, size_t n);       /* 4.11.2.1 */
  39 extern size_t strlen (const char *s);                           /* 4.11.6.3 */
  40 extern void *malloc (size_t size);                              /* 4.10.3.3 */
  41 extern void *realloc (void *ptr, size_t size);                  /* 4.10.3.4 */
  42 extern void free (void *ptr);                                   /* 4.10.3.2 */
  43 extern char *strdup (const char *s);                            /* Non-ANSI */
  44
  45 #else   /* !__STDC__ */
  46
  47 #if !defined _WIN32 || defined __GNUC__
  48 extern char *memcpy ();         /* Copy memory region */
  49 extern int strlen ();           /* Count length of string */
  50 extern char *malloc ();         /* Standard memory allocater */
  51 extern char *realloc ();        /* Standard memory reallocator */
  52 extern void free ();            /* Free malloc'd memory */
  53 extern char *strdup ();         /* Duplicate a string */
  54 #endif
  55
  56 #endif  /* __STDC__ */
  57
  58 #include "alloca-conf.h"
  59
  60 #ifndef NULL
  61 #define NULL 0
  62 #endif
  63
  64 #ifndef EOS
  65 #define EOS '\0'
  66 #endif
  67
  68 #define INITIAL_MAXARGC 8       /* Number of args + NULL in initial argv */
  69
  70
  71 /*
  72
  73 NAME
  74
  75         dupargv -- duplicate an argument vector
  76
  77 SYNOPSIS
  78
  79         char **dupargv (vector)
  80         char **vector;
  81
  82 DESCRIPTION
  83
  84         Duplicate an argument vector.  Simply scans through the
  85         vector, duplicating each argument until the
  86         terminating NULL is found.
  87
  88 RETURNS
  89
  90         Returns a pointer to the argument vector if
  91         successful. Returns NULL if there is insufficient memory to
  92         complete building the argument vector.
  93
  94 */
  95
  96 char **
  97 dupargv (argv)
  98      char **argv;
  99 {
 100   int argc;
 101   char **copy;
 102
 103   if (argv == NULL)
 104     return NULL;
 105
 106   /* the vector */
 107   for (argc = 0; argv[argc] != NULL; argc++);
 108   copy = (char **) malloc ((argc + 1) * sizeof (char *));
 109   if (copy == NULL)
 110     return NULL;
 111
 112   /* the strings */
 113   for (argc = 0; argv[argc] != NULL; argc++)
 114     {
 115       int len = strlen (argv[argc]);
 116       copy[argc] = malloc (sizeof (char *) * (len + 1));
 117       if (copy[argc] == NULL)
 118         {
 119           freeargv (copy);
 120           return NULL;
 121         }
 122       strcpy (copy[argc], argv[argc]);
 123     }
 124   copy[argc] = NULL;
 125   return copy;
 126 }
 127
 128 /*
 129
 130 NAME
 131
 132         freeargv -- free an argument vector
 133
 134 SYNOPSIS
 135
 136         void freeargv (vector)
 137         char **vector;
 138
 139 DESCRIPTION
 140
 141         Free an argument vector that was built using buildargv.  Simply scans
 142         through the vector, freeing the memory for each argument until the
 143         terminating NULL is found, and then frees the vector itself.
 144
 145 RETURNS
 146
 147         No value.
 148
 149 */
 150
 151 void freeargv (vector)
 152 char **vector;
 153 {
 154   register char **scan;
 155
 156   if (vector != NULL)
 157     {
 158       for (scan = vector; *scan != NULL; scan++)
 159         {
 160           free (*scan);
 161         }
 162       free (vector);
 163     }
 164 }
 165
 166 /*
 167
 168 NAME
 169
 170         buildargv -- build an argument vector from a string
 171
 172 SYNOPSIS
 173
 174         char **buildargv (sp)
 175         char *sp;
 176
 177 DESCRIPTION
 178
 179         Given a pointer to a string, parse the string extracting fields
 180         separated by whitespace and optionally enclosed within either single
 181         or double quotes (which are stripped off), and build a vector of
 182         pointers to copies of the string for each field.  The input string
 183         remains unchanged.
 184
 185         All of the memory for the pointer array and copies of the string
 186         is obtained from malloc.  All of the memory can be returned to the
 187         system with the single function call freeargv, which takes the
 188         returned result of buildargv, as it's argument.
 189
 190         The memory for the argv array is dynamically expanded as necessary.
 191
 192 RETURNS
 193
 194         Returns a pointer to the argument vector if successful. Returns NULL
 195         if the input string pointer is NULL or if there is insufficient
 196         memory to complete building the argument vector.
 197
 198 NOTES
 199
 200         In order to provide a working buffer for extracting arguments into,
 201         with appropriate stripping of quotes and translation of backslash
 202         sequences, we allocate a working buffer at least as long as the input
 203         string.  This ensures that we always have enough space in which to
 204         work, since the extracted arg is never larger than the input string.
 205
 206         If the input is a null string (as opposed to a NULL pointer), then
 207         buildarg returns an argv that has one arg, a null string.
 208
 209         Argv is always kept terminated with a NULL arg pointer, so it can
 210         be passed to freeargv at any time, or returned, as appropriate.
 211 */
 212
 213 char **buildargv (input)
 214 char *input;
 215 {
 216   char *arg;
 217   char *copybuf;
 218   int squote = 0;
 219   int dquote = 0;
 220   int bsquote = 0;
 221   int argc = 0;
 222   int maxargc = 0;
 223   char **argv = NULL;
 224   char **nargv;
 225
 226   if (input != NULL)
 227     {
 228       copybuf = (char *) alloca (strlen (input) + 1);
 229       /* Is a do{}while to always execute the loop once.  Always return an
 230          argv, even for null strings.  See NOTES above, test case below. */
 231       do
 232         {
 233           /* Pick off argv[argc] */
 234           while (isspace (*input))
 235             {
 236               input++;
 237             }
 238           if ((maxargc == 0) || (argc >= (maxargc - 1)))
 239             {
 240               /* argv needs initialization, or expansion */
 241               if (argv == NULL)
 242                 {
 243                   maxargc = INITIAL_MAXARGC;
 244                   nargv = (char **) malloc (maxargc * sizeof (char *));
 245                 }
 246               else
 247                 {
 248                   maxargc *= 2;
 249                   nargv = (char **) realloc (argv, maxargc * sizeof (char *));
 250                 }
 251               if (nargv == NULL)
 252                 {
 253                   if (argv != NULL)
 254                     {
 255                       freeargv (argv);
 256                       argv = NULL;
 257                     }
 258                   break;
 259                 }
 260               argv = nargv;
 261               argv[argc] = NULL;
 262             }
 263           /* Begin scanning arg */
 264           arg = copybuf;
 265           while (*input != EOS)
 266             {
 267               if (isspace (*input) && !squote && !dquote && !bsquote)
 268                 {
 269                   break;
 270                 }
 271               else
 272                 {
 273                   if (bsquote)
 274                     {
 275                       bsquote = 0;
 276                       *arg++ = *input;
 277                     }
 278                   else if (*input == '\\')
 279                     {
 280                       bsquote = 1;
 281                     }
 282                   else if (squote)
 283                     {
 284                       if (*input == '\'')
 285                         {
 286                           squote = 0;
 287                         }
 288                       else
 289                         {
 290                           *arg++ = *input;
 291                         }
 292                     }
 293                   else if (dquote)
 294                     {
 295                       if (*input == '"')
 296                         {
 297                           dquote = 0;
 298                         }
 299                       else
 300                         {
 301                           *arg++ = *input;
 302                         }
 303                     }
 304                   else
 305                     {
 306                       if (*input == '\'')
 307                         {
 308                           squote = 1;
 309                         }
 310                       else if (*input == '"')
 311                         {
 312                           dquote = 1;
 313                         }
 314                       else
 315                         {
 316                           *arg++ = *input;
 317                         }
 318                     }
 319                   input++;
 320                 }
 321             }
 322           *arg = EOS;
 323           argv[argc] = strdup (copybuf);
 324           if (argv[argc] == NULL)
 325             {
 326               freeargv (argv);
 327               argv = NULL;
 328               break;
 329             }
 330           argc++;
 331           argv[argc] = NULL;
 332
 333           while (isspace (*input))
 334             {
 335               input++;
 336             }
 337         }
 338       while (*input != EOS);
 339     }
 340   return (argv);
 341 }
 342
 343 #ifdef MAIN
 344
 345 /* Simple little test driver. */
 346
 347 static char *tests[] =
 348 {
 349   "a simple command line",
 350   "arg 'foo' is single quoted",
 351   "arg \"bar\" is double quoted",
 352   "arg \"foo bar\" has embedded whitespace",
 353   "arg 'Jack said \\'hi\\'' has single quotes",
 354   "arg 'Jack said \\\"hi\\\"' has double quotes",
 355   "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",
 356
 357   /* This should be expanded into only one argument.  */
 358   "trailing-whitespace ",
 359
 360   "",
 361   NULL
 362 };
 363
 364 main ()
 365 {
 366   char **argv;
 367   char **test;
 368   char **targs;
 369
 370   for (test = tests; *test != NULL; test++)
 371     {
 372       printf ("buildargv(\"%s\")\n", *test);
 373       if ((argv = buildargv (*test)) == NULL)
 374         {
 375           printf ("failed!\n\n");
 376         }
 377       else
 378         {
 379           for (targs = argv; *targs != NULL; targs++)
 380             {
 381               printf ("\t\"%s\"\n", *targs);
 382             }
 383           printf ("\n");
 384         }
 385       freeargv (argv);
 386     }
 387
 388 }
 389
 390 #endif  /* MAIN */