lib/argmatch.c

   1 /* argmatch.c -- find a match for a string in an array
   2    Copyright (C) 1990, 1997 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; see the file COPYING.
  16    If not, write to the Free Software Foundation,
  17    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  18
  19 /* Written by David MacKenzie <djm@gnu.ai.mit.edu> */
  20
  21 #if HAVE_CONFIG_H
  22 # include <config.h>
  23 #endif
  24
  25 #include <argmatch.h>
  26
  27 #include <sys/types.h>
  28
  29 #include <stdio.h>
  30 #if HAVE_STRING_H
  31 # include <string.h>
  32 #else
  33 # include <strings.h>
  34 #endif
  35
  36 /* If ARG is an unambiguous match for an element of the
  37    null-terminated array OPTLIST, return the index in OPTLIST
  38    of the matched element, else -1 if it does not match any element
  39    or -2 if it is ambiguous (is a prefix of more than one element).  */
  40
  41 int
  42 argmatch (const char *arg, const char *const *optlist)
  43 {
  44   int i;                        /* Temporary index in OPTLIST.  */
  45   size_t arglen;                /* Length of ARG.  */
  46   int matchind = -1;            /* Index of first nonexact match.  */
  47   int ambiguous = 0;            /* If nonzero, multiple nonexact match(es).  */
  48
  49   arglen = strlen (arg);
  50
  51   /* Test all elements for either exact match or abbreviated matches.  */
  52   for (i = 0; optlist[i]; i++)
  53     {
  54       if (!strncmp (optlist[i], arg, arglen))
  55         {
  56           if (strlen (optlist[i]) == arglen)
  57             /* Exact match found.  */
  58             return i;
  59           else if (matchind == -1)
  60             /* First nonexact match found.  */
  61             matchind = i;
  62           else
  63             /* Second nonexact match found.  */
  64             ambiguous = 1;
  65         }
  66     }
  67   if (ambiguous)
  68     return -2;
  69   else
  70     return matchind;
  71 }
  72
  73 /* Error reporting for argmatch.
  74    KIND is a description of the type of entity that was being matched.
  75    VALUE is the invalid value that was given.
  76    PROBLEM is the return value from argmatch.  */
  77
  78 void
  79 invalid_arg (const char *kind, const char *value, int problem)
  80 {
  81   const char *fmt = (problem == -1
  82                      ? "%s: invalid %s `%s'\n"
  83                      : "%s: ambiguous %s `%s'\n");
  84   fprintf (stderr, fmt, program_name, kind, value);
  85 }