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 /* based on @(#)genget.c 8.1 (Berkeley) 6/4/93 */
35
36 #include <autoconf.h>
37
38 #include <ctype.h>
39 #include "misc.h"
40
41 #define LOWER(x) (isupper((int) x) ? tolower((int) 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(s1,s2)49 isprefix(s1, s2)
50 register char *s1, *s2;
51 {
52 char *os1;
53 register char c1, c2;
54
55 if (*s1 == '\0')
56 return(-1);
57 os1 = s1;
58 c1 = *s1;
59 c2 = *s2;
60 while (LOWER(c1) == LOWER(c2)) {
61 if (c1 == '\0')
62 break;
63 c1 = *++s1;
64 c2 = *++s2;
65 }
66 return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1)));
67 }
68
69 static char *ambiguous; /* special return value for command routines */
70
71 char **
genget(name,table,stlen)72 genget(name, table, stlen)
73 char *name; /* name to match */
74 char **table; /* name entry in table */
75 int stlen;
76 {
77 register char **c, **found;
78 register 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(s)100 Ambiguous(s)
101 void *s;
102 {
103 return((char **)s == &ambiguous);
104 }
105