xref: /openbsd/gnu/usr.bin/cvs/lib/argmatch.c (revision e5dd7070)
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 /* Written by David MacKenzie <djm@ai.mit.edu> */
15 
16 #ifdef HAVE_CONFIG_H
17 #include "config.h"
18 #endif
19 
20 #include <sys/types.h>
21 
22 #include <stdio.h>
23 #ifdef STDC_HEADERS
24 #include <string.h>
25 #endif
26 
27 extern char *program_name;
28 
29 /* If ARG is an unambiguous match for an element of the
30    null-terminated array OPTLIST, return the index in OPTLIST
31    of the matched element, else -1 if it does not match any element
32    or -2 if it is ambiguous (is a prefix of more than one element). */
33 
34 int
35 argmatch (arg, optlist)
36      char *arg;
37      char **optlist;
38 {
39   int i;			/* Temporary index in OPTLIST. */
40   size_t arglen;		/* Length of ARG. */
41   int matchind = -1;		/* Index of first nonexact match. */
42   int ambiguous = 0;		/* If nonzero, multiple nonexact match(es). */
43 
44   arglen = strlen (arg);
45 
46   /* Test all elements for either exact match or abbreviated matches.  */
47   for (i = 0; optlist[i]; i++)
48     {
49       if (!strncmp (optlist[i], arg, arglen))
50 	{
51 	  if (strlen (optlist[i]) == arglen)
52 	    /* Exact match found.  */
53 	    return i;
54 	  else if (matchind == -1)
55 	    /* First nonexact match found.  */
56 	    matchind = i;
57 	  else
58 	    /* Second nonexact match found.  */
59 	    ambiguous = 1;
60 	}
61     }
62   if (ambiguous)
63     return -2;
64   else
65     return matchind;
66 }
67 
68 /* Error reporting for argmatch.
69    KIND is a description of the type of entity that was being matched.
70    VALUE is the invalid value that was given.
71    PROBLEM is the return value from argmatch. */
72 
73 void
74 invalid_arg (kind, value, problem)
75      char *kind;
76      char *value;
77      int problem;
78 {
79   fprintf (stderr, "%s: ", program_name);
80   if (problem == -1)
81     fprintf (stderr, "invalid");
82   else				/* Assume -2. */
83     fprintf (stderr, "ambiguous");
84   fprintf (stderr, " %s `%s'\n", kind, value);
85 }
86