1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35
36#ifdef __FBSDID
37__FBSDID("$FreeBSD: src/crypto/telnet/libtelnet/genget.c,v 1.2.8.2 2002/04/13 10:59:07 markm Exp $");
38#endif
39
40#ifndef lint
41#if 0
42static const char sccsid[] = "@(#)genget.c	8.2 (Berkeley) 5/30/95";
43#endif
44#endif /* not lint */
45
46
47#include <ctype.h>
48
49#include "misc-proto.h"
50
51#define	LOWER(x) (isupper(x) ? tolower(x) : (x))
52/*
53 * The prefix function returns 0 if *s1 is not a prefix
54 * of *s2.  If *s1 exactly matches *s2, the negative of
55 * the length is returned.  If *s1 is a prefix of *s2,
56 * the length of *s1 is returned.
57 */
58int
59isprefix(char *s1, const char *s2)
60{
61	char *os1;
62	char c1, c2;
63
64	if (*s1 == '\0')
65		return(-1);
66	os1 = s1;
67	c1 = *s1;
68	c2 = *s2;
69	while (LOWER(c1) == LOWER(c2)) {
70		if (c1 == '\0')
71			break;
72		c1 = *++s1;
73		c2 = *++s2;
74	}
75	return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1)));
76}
77
78static char *ambiguous;		/* special return value for command routines */
79
80char **
81genget(char *name, char **table, int stlen)
82{
83	char **c, **found;
84	int n;
85
86	if (name == 0)
87	    return 0;
88
89	found = 0;
90	for (c = table; *c != 0; c = (char **)((char *)c + stlen)) {
91		if ((n = isprefix(name, *c)) == 0)
92			continue;
93		if (n < 0)		/* exact match */
94			return(c);
95		if (found)
96			return(&ambiguous);
97		found = c;
98	}
99	return(found);
100}
101
102/*
103 * Function call version of Ambiguous()
104 */
105int
106Ambiguous(char **s)
107{
108	return(s == &ambiguous);
109}
110