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 #include <sys/cdefs.h> 35 36 __FBSDID("$FreeBSD$"); 37 38 #ifndef lint 39 #if 0 40 static const char sccsid[] = "@(#)genget.c 8.2 (Berkeley) 5/30/95"; 41 #endif 42 #endif /* not lint */ 43 44 45 #include <ctype.h> 46 47 #include "misc-proto.h" 48 49 #define LOWER(x) (isupper(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(char *s1, const char *s2) 58 { 59 char *os1; 60 char c1, c2; 61 62 if (*s1 == '\0') 63 return(-1); 64 os1 = s1; 65 c1 = *s1; 66 c2 = *s2; 67 while (LOWER(c1) == LOWER(c2)) { 68 if (c1 == '\0') 69 break; 70 c1 = *++s1; 71 c2 = *++s2; 72 } 73 return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1))); 74 } 75 76 static char *ambiguous; /* special return value for command routines */ 77 78 char ** 79 genget(char *name, char **table, int stlen) 80 { 81 char **c, **found; 82 int n; 83 84 if (name == 0) 85 return 0; 86 87 found = 0; 88 for (c = table; *c != 0; c = (char **)((char *)c + stlen)) { 89 if ((n = isprefix(name, *c)) == 0) 90 continue; 91 if (n < 0) /* exact match */ 92 return(c); 93 if (found) 94 return(&ambiguous); 95 found = c; 96 } 97 return(found); 98 } 99 100 /* 101 * Function call version of Ambiguous() 102 */ 103 int 104 Ambiguous(char **s) 105 { 106 return(s == &ambiguous); 107 } 108