1 /* $OpenBSD: genget.c,v 1.2 2003/06/02 19:38:25 millert Exp $ */
2
3 /*-
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #ifndef lint
33 /* from: static char sccsid[] = "@(#)genget.c 8.2 (Berkeley) 5/30/95"; */
34 /* from: static char *rcsid = "$NetBSD: genget.c,v 1.5 1996/02/24 01:15:21 jtk Exp $"; */
35 static char *rcsid = "$OpenBSD: genget.c,v 1.2 2003/06/02 19:38:25 millert Exp $";
36 #endif /* not lint */
37
38 /* $KTH: genget.c,v 1.6 1997/05/04 09:01:34 assar Exp $ */
39
40 #include <ctype.h>
41 #include "misc-proto.h"
42
43 #define LOWER(x) (isupper((int)x) ? tolower((int)x) : (x))
44 /*
45 * The prefix function returns 0 if *s1 is not a prefix
46 * of *s2. If *s1 exactly matches *s2, the negative of
47 * the length is returned. If *s1 is a prefix of *s2,
48 * the length of *s1 is returned.
49 */
50 int
isprefix(char * s1,char * s2)51 isprefix(char *s1, char *s2)
52 {
53 char *os1;
54 char c1, c2;
55
56 if (*s1 == '\0')
57 return(-1);
58 os1 = s1;
59 c1 = *s1;
60 c2 = *s2;
61 while (LOWER(c1) == LOWER(c2)) {
62 if (c1 == '\0')
63 break;
64 c1 = *++s1;
65 c2 = *++s2;
66 }
67 return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1)));
68 }
69
70 static char *ambiguous; /* special return value for command routines */
71
72 char **
genget(char * name,char ** table,int stlen)73 genget(char *name, char **table, int stlen)
74 /* name to match */
75 /* name entry in table */
76
77 {
78 char **c, **found;
79 int n;
80
81 if (name == 0)
82 return 0;
83
84 found = 0;
85 for (c = table; *c != 0; c = (char **)((char *)c + stlen)) {
86 if ((n = isprefix(name, *c)) == 0)
87 continue;
88 if (n < 0) /* exact match */
89 return(c);
90 if (found)
91 return(&ambiguous);
92 found = c;
93 }
94 return(found);
95 }
96
97 /*
98 * Function call version of Ambiguous()
99 */
100 int
Ambiguous(void * s)101 Ambiguous(void *s)
102 {
103 return((char **)s == &ambiguous);
104 }
105