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 #ifndef lint 31 #if 0 32 static const char sccsid[] = "@(#)genget.c 8.2 (Berkeley) 5/30/95"; 33 #endif 34 #endif /* not lint */ 35 36 37 #include <ctype.h> 38 39 #include "misc-proto.h" 40 41 #define LOWER(x) (isupper(x) ? tolower(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 49 isprefix(char *s1, const char *s2) 50 { 51 char *os1; 52 char c1, c2; 53 54 if (*s1 == '\0') 55 return(-1); 56 os1 = s1; 57 c1 = *s1; 58 c2 = *s2; 59 while (LOWER(c1) == LOWER(c2)) { 60 if (c1 == '\0') 61 break; 62 c1 = *++s1; 63 c2 = *++s2; 64 } 65 return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1))); 66 } 67 68 static char *ambiguous; /* special return value for command routines */ 69 70 char ** 71 genget(char *name, char **table, int stlen) 72 { 73 char **c, **found; 74 int n; 75 76 if (name == 0) 77 return 0; 78 79 found = 0; 80 for (c = table; *c != 0; c = (char **)((char *)c + stlen)) { 81 if ((n = isprefix(name, *c)) == 0) 82 continue; 83 if (n < 0) /* exact match */ 84 return(c); 85 if (found) 86 return(&ambiguous); 87 found = c; 88 } 89 return(found); 90 } 91 92 /* 93 * Function call version of Ambiguous() 94 */ 95 int 96 Ambiguous(char **s) 97 { 98 return(s == &ambiguous); 99 } 100