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. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31
32 __FBSDID("$FreeBSD$");
33
34 #ifndef lint
35 #if 0
36 static const char sccsid[] = "@(#)genget.c 8.2 (Berkeley) 5/30/95";
37 #endif
38 #endif /* not lint */
39
40
41 #include <ctype.h>
42
43 #include "misc-proto.h"
44
45 #define LOWER(x) (isupper(x) ? tolower(x) : (x))
46 /*
47 * The prefix function returns 0 if *s1 is not a prefix
48 * of *s2. If *s1 exactly matches *s2, the negative of
49 * the length is returned. If *s1 is a prefix of *s2,
50 * the length of *s1 is returned.
51 */
52 int
isprefix(char * s1,const char * s2)53 isprefix(char *s1, const char *s2)
54 {
55 char *os1;
56 char c1, c2;
57
58 if (*s1 == '\0')
59 return(-1);
60 os1 = s1;
61 c1 = *s1;
62 c2 = *s2;
63 while (LOWER(c1) == LOWER(c2)) {
64 if (c1 == '\0')
65 break;
66 c1 = *++s1;
67 c2 = *++s2;
68 }
69 return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1)));
70 }
71
72 static char *ambiguous; /* special return value for command routines */
73
74 char **
genget(char * name,char ** table,int stlen)75 genget(char *name, char **table, int stlen)
76 {
77 char **c, **found;
78 int n;
79
80 if (name == 0)
81 return 0;
82
83 found = 0;
84 for (c = table; *c != 0; c = (char **)((char *)c + stlen)) {
85 if ((n = isprefix(name, *c)) == 0)
86 continue;
87 if (n < 0) /* exact match */
88 return(c);
89 if (found)
90 return(&ambiguous);
91 found = c;
92 }
93 return(found);
94 }
95
96 /*
97 * Function call version of Ambiguous()
98 */
99 int
Ambiguous(char ** s)100 Ambiguous(char **s)
101 {
102 return(s == &ambiguous);
103 }
104