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 #ifndef lint
31 #if 0
32 static const char sccsid[] = "@(#)genget.c 8.2 (Berkeley) 5/30/95";
33 #endif
34 #endif /* not lint */
35
36
37 #include <ctype.h>
38
39 #include "misc-proto.h"
40
41 #define LOWER(x) (isupper(x) ? tolower(x) : (x))
42 /*
43 * The prefix function returns 0 if *s1 is not a prefix
44 * of *s2. If *s1 exactly matches *s2, the negative of
45 * the length is returned. If *s1 is a prefix of *s2,
46 * the length of *s1 is returned.
47 */
48 int
isprefix(char * s1,const char * s2)49 isprefix(char *s1, const char *s2)
50 {
51 char *os1;
52 char c1, c2;
53
54 if (*s1 == '\0')
55 return(-1);
56 os1 = s1;
57 c1 = *s1;
58 c2 = *s2;
59 while (LOWER(c1) == LOWER(c2)) {
60 if (c1 == '\0')
61 break;
62 c1 = *++s1;
63 c2 = *++s2;
64 }
65 return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1)));
66 }
67
68 static char *ambiguous; /* special return value for command routines */
69
70 char **
genget(char * name,char ** table,int stlen)71 genget(char *name, char **table, int stlen)
72 {
73 char **c, **found;
74 int n;
75
76 if (name == 0)
77 return 0;
78
79 found = 0;
80 for (c = table; *c != 0; c = (char **)((char *)c + stlen)) {
81 if ((n = isprefix(name, *c)) == 0)
82 continue;
83 if (n < 0) /* exact match */
84 return(c);
85 if (found)
86 return(&ambiguous);
87 found = c;
88 }
89 return(found);
90 }
91
92 /*
93 * Function call version of Ambiguous()
94 */
95 int
Ambiguous(char ** s)96 Ambiguous(char **s)
97 {
98 return(s == &ambiguous);
99 }
100