1 /* $NetBSD: genget.c,v 1.8 1998/11/06 19:20:12 christos 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 #if 0 39 static char sccsid[] = "@(#)genget.c 8.2 (Berkeley) 5/30/95"; 40 #else 41 __RCSID("$NetBSD: genget.c,v 1.8 1998/11/06 19:20:12 christos Exp $"); 42 #endif 43 #endif /* not lint */ 44 45 46 #include <ctype.h> 47 #include "misc.h" 48 49 #define LOWER(x) (isupper((unsigned char)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 57 isprefix(s1, s2) 58 register char *s1, *s2; 59 { 60 char *os1; 61 register char c1, c2; 62 63 if (*s1 == '\0') 64 return(-1); 65 os1 = s1; 66 c1 = *s1; 67 c2 = *s2; 68 while (LOWER(c1) == LOWER(c2)) { 69 if (c1 == '\0') 70 break; 71 c1 = *++s1; 72 c2 = *++s2; 73 } 74 return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1))); 75 } 76 77 static char *ambiguous; /* special return value for command routines */ 78 79 char ** 80 genget(name, table, stlen) 81 char *name; /* name to match */ 82 char **table; /* name entry in table */ 83 int stlen; 84 { 85 register char **c, **found; 86 register int n; 87 88 if (name == 0) 89 return 0; 90 91 found = 0; 92 for (c = table; *c != 0; c = (char **)((char *)c + stlen)) { 93 if ((n = isprefix(name, *c)) == 0) 94 continue; 95 if (n < 0) /* exact match */ 96 return(c); 97 if (found) 98 return(&ambiguous); 99 found = c; 100 } 101 return(found); 102 } 103 104 /* 105 * Function call version of Ambiguous() 106 */ 107 int 108 Ambiguous(s) 109 void *s; 110 { 111 return(s == &ambiguous); 112 } 113