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