lib/argmatch.c

   1 /* argmatch.c -- find a match for a string in an array
   2    Copyright (C) 1990 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; if not, write to the Free Software
  16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  17
  18 /* Written by David MacKenzie <djm@ai.mit.edu> */
  19
  20 #include <stdio.h>
  21 #ifdef STDC_HEADERS
  22 #include <string.h>
  23 #endif
  24
  25 extern char *program_name;
  26
  27 /* If ARG is an unambiguous match for an element of the
  28    null-terminated array OPTLIST, return the index in OPTLIST
  29    of the matched element, else -1 if it does not match any element
  30    or -2 if it is ambiguous (is a prefix of more than one element).  */
  31
  32 int
  33 argmatch (arg, optlist)
  34      char *arg;
  35      char **optlist;
  36 {
  37   int i;                        /* Temporary index in OPTLIST.  */
  38   int arglen;                   /* Length of ARG.  */
  39   int matchind = -1;            /* Index of first nonexact match.  */
  40   int ambiguous = 0;            /* If nonzero, multiple nonexact match(es).  */
  41
  42   arglen = strlen (arg);
  43
  44   /* Test all elements for either exact match or abbreviated matches.  */
  45   for (i = 0; optlist[i]; i++)
  46     {
  47       if (!strncmp (optlist[i], arg, arglen))
  48         {
  49           if (strlen (optlist[i]) == arglen)
  50             /* Exact match found.  */
  51             return i;
  52           else if (matchind == -1)
  53             /* First nonexact match found.  */
  54             matchind = i;
  55           else
  56             /* Second nonexact match found.  */
  57             ambiguous = 1;
  58         }
  59     }
  60   if (ambiguous)
  61     return -2;
  62   else
  63     return matchind;
  64 }
  65
  66 /* Error reporting for argmatch.
  67    KIND is a description of the type of entity that was being matched.
  68    VALUE is the invalid value that was given.
  69    PROBLEM is the return value from argmatch.  */
  70
  71 void
  72 invalid_arg (kind, value, problem)
  73      char *kind;
  74      char *value;
  75      int problem;
  76 {
  77   fprintf (stderr, "%s: ", program_name);
  78   if (problem == -1)
  79     fprintf (stderr, "invalid");
  80   else                          /* Assume -2.  */
  81     fprintf (stderr, "ambiguous");
  82   fprintf (stderr, " %s `%s'\n", kind, value);
  83 }