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 #ifdef HAVE_CONFIG_H
  21 #include <config.h>
  22 #endif
  23
  24 #include <sys/types.h>
  25
  26 #include <stdio.h>
  27 #ifdef STDC_HEADERS
  28 #include <string.h>
  29 #endif
  30
  31 extern char *program_name;
  32
  33 /* If ARG is an unambiguous match for an element of the
  34    null-terminated array OPTLIST, return the index in OPTLIST
  35    of the matched element, else -1 if it does not match any element
  36    or -2 if it is ambiguous (is a prefix of more than one element).  */
  37
  38 int
  39 argmatch (arg, optlist)
  40      const char *arg;
  41      const char *const *optlist;
  42 {
  43   int i;                        /* Temporary index in OPTLIST.  */
  44   size_t arglen;                /* Length of ARG.  */
  45   int matchind = -1;            /* Index of first nonexact match.  */
  46   int ambiguous = 0;            /* If nonzero, multiple nonexact match(es).  */
  47
  48   arglen = strlen (arg);
  49
  50   /* Test all elements for either exact match or abbreviated matches.  */
  51   for (i = 0; optlist[i]; i++)
  52     {
  53       if (!strncmp (optlist[i], arg, arglen))
  54         {
  55           if (strlen (optlist[i]) == arglen)
  56             /* Exact match found.  */
  57             return i;
  58           else if (matchind == -1)
  59             /* First nonexact match found.  */
  60             matchind = i;
  61           else
  62             /* Second nonexact match found.  */
  63             ambiguous = 1;
  64         }
  65     }
  66   if (ambiguous)
  67     return -2;
  68   else
  69     return matchind;
  70 }
  71
  72 /* Error reporting for argmatch.
  73    KIND is a description of the type of entity that was being matched.
  74    VALUE is the invalid value that was given.
  75    PROBLEM is the return value from argmatch.  */
  76
  77 void
  78 invalid_arg (kind, value, problem)
  79      const char *kind;
  80      const char *value;
  81      int problem;
  82 {
  83   fprintf (stderr, "%s: ", program_name);
  84   if (problem == -1)
  85     fprintf (stderr, "invalid");
  86   else                          /* Assume -2.  */
  87     fprintf (stderr, "ambiguous");
  88   fprintf (stderr, " %s `%s'\n", kind, value);
  89 }