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 __FBSDID("$FreeBSD$");
37
38 #ifndef lint
39 #if 0
40 static const char sccsid[] = "@(#)genget.c 8.2 (Berkeley) 5/30/95";
41 #endif
42 #endif /* not lint */
43
44
45 #include <ctype.h>
46
47 #include "misc-proto.h"
48
49 #define LOWER(x) (isupper(x) ? tolower(x) : (x))
50 /*
51 * The prefix function returns 0 if *s1 is not a prefix
52 * of *s2. If *s1 exactly matches *s2, the negative of
53 * the length is returned. If *s1 is a prefix of *s2,
54 * the length of *s1 is returned.
55 */
56 int
isprefix(char * s1,const char * s2)57 isprefix(char *s1, const char *s2)
58 {
59 char *os1;
60 char c1, c2;
61
62 if (*s1 == '\0')
63 return(-1);
64 os1 = s1;
65 c1 = *s1;
66 c2 = *s2;
67 while (LOWER(c1) == LOWER(c2)) {
68 if (c1 == '\0')
69 break;
70 c1 = *++s1;
71 c2 = *++s2;
72 }
73 return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1)));
74 }
75
76 static char *ambiguous; /* special return value for command routines */
77
78 char **
genget(char * name,char ** table,int stlen)79 genget(char *name, char **table, int stlen)
80 {
81 char **c, **found;
82 int n;
83
84 if (name == 0)
85 return 0;
86
87 found = 0;
88 for (c = table; *c != 0; c = (char **)((char *)c + stlen)) {
89 if ((n = isprefix(name, *c)) == 0)
90 continue;
91 if (n < 0) /* exact match */
92 return(c);
93 if (found)
94 return(&ambiguous);
95 found = c;
96 }
97 return(found);
98 }
99
100 /*
101 * Function call version of Ambiguous()
102 */
103 int
Ambiguous(char ** s)104 Ambiguous(char **s)
105 {
106 return(s == &ambiguous);
107 }
108