gnu/dist/gettext/gettext-tools/lib/argmatch.c

   1 /* argmatch.c -- find a match for a string in an array
   2
   3    Copyright (C) 1990, 1998, 1999, 2001, 2002, 2003, 2004 Free
   4    Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    This program 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
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software Foundation,
  18    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 /* Written by David MacKenzie <djm@ai.mit.edu>
  21    Modified by Akim Demaille <demaille@inf.enst.fr> */
  22
  23 #if HAVE_CONFIG_H
  24 # include <config.h>
  25 #endif
  26
  27 /* Specification.  */
  28 #include "argmatch.h"
  29
  30 #include <stdbool.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34
  35 #include "gettext.h"
  36 #define _(msgid) gettext (msgid)
  37
  38 #include "error.h"
  39 #include "exit.h"
  40 #include "quotearg.h"
  41 #include "quote.h"
  42
  43 #if USE_UNLOCKED_IO
  44 # include "unlocked-io.h"
  45 #endif
  46
  47 /* When reporting an invalid argument, show nonprinting characters
  48    by using the quoting style ARGMATCH_QUOTING_STYLE.  Do not use
  49    literal_quoting_style.  */
  50 #ifndef ARGMATCH_QUOTING_STYLE
  51 # define ARGMATCH_QUOTING_STYLE locale_quoting_style
  52 #endif
  53
  54 /* Non failing version of argmatch call this function after failing. */
  55 #ifndef ARGMATCH_DIE
  56 # include "exitfail.h"
  57 # define ARGMATCH_DIE exit (exit_failure)
  58 #endif
  59
  60 #ifdef ARGMATCH_DIE_DECL
  61 ARGMATCH_DIE_DECL;
  62 #endif
  63
  64 static void
  65 __argmatch_die (void)
  66 {
  67   ARGMATCH_DIE;
  68 }
  69
  70 /* Used by XARGMATCH and XARGCASEMATCH.  See description in argmatch.h.
  71    Default to __argmatch_die, but allow caller to change this at run-time. */
  72 argmatch_exit_fn argmatch_die = __argmatch_die;
  73
  74 \f
  75 /* If ARG is an unambiguous match for an element of the
  76    null-terminated array ARGLIST, return the index in ARGLIST
  77    of the matched element, else -1 if it does not match any element
  78    or -2 if it is ambiguous (is a prefix of more than one element).
  79
  80    If VALLIST is none null, use it to resolve ambiguities limited to
  81    synonyms, i.e., for
  82      "yes", "yop" -> 0
  83      "no", "nope" -> 1
  84    "y" is a valid argument, for `0', and "n" for `1'.  */
  85
  86 ptrdiff_t
  87 argmatch (const char *arg, const char *const *arglist,
  88           const char *vallist, size_t valsize)
  89 {
  90   size_t i;                     /* Temporary index in ARGLIST.  */
  91   size_t arglen;                /* Length of ARG.  */
  92   ptrdiff_t matchind = -1;      /* Index of first nonexact match.  */
  93   bool ambiguous = false;       /* If true, multiple nonexact match(es).  */
  94
  95   arglen = strlen (arg);
  96
  97   /* Test all elements for either exact match or abbreviated matches.  */
  98   for (i = 0; arglist[i]; i++)
  99     {
 100       if (!strncmp (arglist[i], arg, arglen))
 101         {
 102           if (strlen (arglist[i]) == arglen)
 103             /* Exact match found.  */
 104             return i;
 105           else if (matchind == -1)
 106             /* First nonexact match found.  */
 107             matchind = i;
 108           else
 109             {
 110               /* Second nonexact match found.  */
 111               if (vallist == NULL
 112                   || memcmp (vallist + valsize * matchind,
 113                              vallist + valsize * i, valsize))
 114                 {
 115                   /* There is a real ambiguity, or we could not
 116                      disambiguate. */
 117                   ambiguous = true;
 118                 }
 119             }
 120         }
 121     }
 122   if (ambiguous)
 123     return -2;
 124   else
 125     return matchind;
 126 }
 127
 128 /* Error reporting for argmatch.
 129    CONTEXT is a description of the type of entity that was being matched.
 130    VALUE is the invalid value that was given.
 131    PROBLEM is the return value from argmatch.  */
 132
 133 void
 134 argmatch_invalid (const char *context, const char *value, ptrdiff_t problem)
 135 {
 136   char const *format = (problem == -1
 137                         ? _("invalid argument %s for %s")
 138                         : _("ambiguous argument %s for %s"));
 139
 140   error (0, 0, format, quotearg_n_style (0, ARGMATCH_QUOTING_STYLE, value),
 141          quote_n (1, context));
 142 }
 143
 144 /* List the valid arguments for argmatch.
 145    ARGLIST is the same as in argmatch.
 146    VALLIST is a pointer to an array of values.
 147    VALSIZE is the size of the elements of VALLIST */
 148 void
 149 argmatch_valid (const char *const *arglist,
 150                 const char *vallist, size_t valsize)
 151 {
 152   size_t i;
 153   const char *last_val = NULL;
 154
 155   /* We try to put synonyms on the same line.  The assumption is that
 156      synonyms follow each other */
 157   fprintf (stderr, _("Valid arguments are:"));
 158   for (i = 0; arglist[i]; i++)
 159     if ((i == 0)
 160         || memcmp (last_val, vallist + valsize * i, valsize))
 161       {
 162         fprintf (stderr, "\n  - `%s'", arglist[i]);
 163         last_val = vallist + valsize * i;
 164       }
 165     else
 166       {
 167         fprintf (stderr, ", `%s'", arglist[i]);
 168       }
 169   putc ('\n', stderr);
 170 }
 171
 172 /* Never failing versions of the previous functions.
 173
 174    CONTEXT is the context for which argmatch is called (e.g.,
 175    "--version-control", or "$VERSION_CONTROL" etc.).  Upon failure,
 176    calls the (supposed never to return) function EXIT_FN. */
 177
 178 ptrdiff_t
 179 __xargmatch_internal (const char *context,
 180                       const char *arg, const char *const *arglist,
 181                       const char *vallist, size_t valsize,
 182                       argmatch_exit_fn exit_fn)
 183 {
 184   ptrdiff_t res = argmatch (arg, arglist, vallist, valsize);
 185   if (res >= 0)
 186     /* Success. */
 187     return res;
 188
 189   /* We failed.  Explain why. */
 190   argmatch_invalid (context, arg, res);
 191   argmatch_valid (arglist, vallist, valsize);
 192   (*exit_fn) ();
 193
 194   return -1; /* To please the compilers. */
 195 }
 196
 197 /* Look for VALUE in VALLIST, an array of objects of size VALSIZE and
 198    return the first corresponding argument in ARGLIST */
 199 const char *
 200 argmatch_to_argument (const char *value,
 201                       const char *const *arglist,
 202                       const char *vallist, size_t valsize)
 203 {
 204   size_t i;
 205
 206   for (i = 0; arglist[i]; i++)
 207     if (!memcmp (value, vallist + valsize * i, valsize))
 208       return arglist[i];
 209   return NULL;
 210 }
 211
 212 #ifdef TEST
 213 /*
 214  * Based on "getversion.c" by David MacKenzie <djm@gnu.ai.mit.edu>
 215  */
 216 char *program_name;
 217
 218 /* When to make backup files.  */
 219 enum backup_type
 220 {
 221   /* Never make backups.  */
 222   no_backups,
 223
 224   /* Make simple backups of every file.  */
 225   simple_backups,
 226
 227   /* Make numbered backups of files that already have numbered backups,
 228      and simple backups of the others.  */
 229   numbered_existing_backups,
 230
 231   /* Make numbered backups of every file.  */
 232   numbered_backups
 233 };
 234
 235 /* Two tables describing arguments (keys) and their corresponding
 236    values */
 237 static const char *const backup_args[] =
 238 {
 239   "no", "none", "off",
 240   "simple", "never",
 241   "existing", "nil",
 242   "numbered", "t",
 243   0
 244 };
 245
 246 static const enum backup_type backup_vals[] =
 247 {
 248   no_backups, no_backups, no_backups,
 249   simple_backups, simple_backups,
 250   numbered_existing_backups, numbered_existing_backups,
 251   numbered_backups, numbered_backups
 252 };
 253
 254 int
 255 main (int argc, const char *const *argv)
 256 {
 257   const char *cp;
 258   enum backup_type backup_type = no_backups;
 259
 260   program_name = (char *) argv[0];
 261
 262   if (argc > 2)
 263     {
 264       fprintf (stderr, "Usage: %s [VERSION_CONTROL]\n", program_name);
 265       exit (1);
 266     }
 267
 268   if ((cp = getenv ("VERSION_CONTROL")))
 269     backup_type = XARGMATCH ("$VERSION_CONTROL", cp,
 270                              backup_args, backup_vals);
 271
 272   if (argc == 2)
 273     backup_type = XARGMATCH (program_name, argv[1],
 274                              backup_args, backup_vals);
 275
 276   printf ("The version control is `%s'\n",
 277           ARGMATCH_TO_ARGUMENT (backup_type, backup_args, backup_vals));
 278
 279   return 0;
 280 }
 281 #endif