1/*
2 * Copyright 2002 Sun Microsystems, Inc.  All rights reserved.
3 * Use is subject to license terms.
4 */
5
6#pragma ident	"%Z%%M%	%I%	%E% SMI"
7
8/*
9 * Copyright (c) 1991, 1993
10 *	The Regents of the University of California.  All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 *    must display the following acknowledgement:
22 *	This product includes software developed by the University of
23 *	California, Berkeley and its contributors.
24 * 4. Neither the name of the University nor the names of its contributors
25 *    may be used to endorse or promote products derived from this software
26 *    without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39 */
40
41#ifndef lint
42static char sccsid[] = "@(#)genget.c	8.1 (Berkeley) 6/4/93";
43#endif /* not lint */
44
45#include <ctype.h>
46#include <sys/types.h>
47
48#define	LOWER(x) (isupper(x) ? tolower(x) : (x))
49
50static char *ambiguous;		/* special return value for command routines */
51
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, 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
78
79/*
80 * Get an entry from the table, from what might be a prefix
81 *
82 * name		= name to match
83 * table	= name entry in table
84 */
85char **
86genget(char *name, char **table, int stlen)
87{
88	register char **c, **found;
89	register int n;
90
91	if (name == 0)
92	    return (0);
93
94	found = 0;
95	/*LINTED*/
96	for (c = table; *c != NULL; c = (char **)((char *)c + stlen)) {
97		if ((n = isprefix(name, *c)) == 0)
98			continue;
99		if (n < 0)		/* exact match */
100			return (c);
101		if (found)
102			return (&ambiguous);
103		found = c;
104	}
105	return (found);
106}
107
108/*
109 * Function call version of Ambiguous()
110 */
111boolean_t
112Ambiguous(void *s)
113{
114	return ((char **)s == &ambiguous);
115}
116