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 (arg, optlist)
  43      const char *arg;
  44      const char *const *optlist;
  45 {
  46   int i;                        /* Temporary index in OPTLIST.  */
  47   size_t arglen;                /* Length of ARG.  */
  48   int matchind = -1;            /* Index of first nonexact match.  */
  49   int ambiguous = 0;            /* If nonzero, multiple nonexact match(es).  */
  50
  51   arglen = strlen (arg);
  52
  53   /* Test all elements for either exact match or abbreviated matches.  */
  54   for (i = 0; optlist[i]; i++)
  55     {
  56       if (!strncmp (optlist[i], arg, arglen))
  57         {
  58           if (strlen (optlist[i]) == arglen)
  59             /* Exact match found.  */
  60             return i;
  61           else if (matchind == -1)
  62             /* First nonexact match found.  */
  63             matchind = i;
  64           else
  65             /* Second nonexact match found.  */
  66             ambiguous = 1;
  67         }
  68     }
  69   if (ambiguous)
  70     return -2;
  71   else
  72     return matchind;
  73 }
  74
  75 /* Error reporting for argmatch.
  76    KIND is a description of the type of entity that was being matched.
  77    VALUE is the invalid value that was given.
  78    PROBLEM is the return value from argmatch.  */
  79
  80 void
  81 invalid_arg (kind, value, problem)
  82      const char *kind;
  83      const char *value;
  84      int problem;
  85 {
  86   fprintf (stderr, "%s: ", program_name);
  87   if (problem == -1)
  88     fprintf (stderr, "invalid");
  89   else                          /* Assume -2.  */
  90     fprintf (stderr, "ambiguous");
  91   fprintf (stderr, " %s `%s'\n", kind, value);
  92 }