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 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, 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 100 Ambiguous(char **s) 101 { 102 return(s == &ambiguous); 103 } 104