1 /* $NetBSD: genget.c,v 1.13 2012/03/21 05:33:27 matt 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)genget.c 8.2 (Berkeley) 5/30/95"; 36 #else 37 __RCSID("$NetBSD: genget.c,v 1.13 2012/03/21 05:33:27 matt Exp $"); 38 #endif 39 #endif /* not lint */ 40 41 42 #include <ctype.h> 43 #include "misc.h" 44 45 #define LOWER(x) (isupper((unsigned char)x) ? tolower((unsigned char)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 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 ** 75 genget( char *name, /* name to match */ 76 char **table, /* name entry in table */ 77 int stlen) 78 { 79 register char **c, **found; 80 register int n; 81 82 if (name == 0) 83 return 0; 84 85 found = 0; 86 for (c = table; *c != 0; c = (char **)((char *)c + stlen)) { 87 if ((n = isprefix(name, *c)) == 0) 88 continue; 89 if (n < 0) /* exact match */ 90 return(c); 91 if (found) 92 return(&ambiguous); 93 found = c; 94 } 95 return(found); 96 } 97 98 /* 99 * Function call version of Ambiguous() 100 */ 101 int 102 Ambiguous(void *s) 103 { 104 return(s == &ambiguous); 105 } 106