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 #ifndef lint 35 #if 0 36 static const char sccsid[] = "@(#)genget.c 8.2 (Berkeley) 5/30/95"; 37 #else 38 static const char rcsid[] = 39 "$FreeBSD$"; 40 #endif 41 #endif /* not lint */ 42 43 44 #include <ctype.h> 45 46 #define LOWER(x) (isupper(x) ? tolower(x) : (x)) 47 /* 48 * The prefix function returns 0 if *s1 is not a prefix 49 * of *s2. If *s1 exactly matches *s2, the negative of 50 * the length is returned. If *s1 is a prefix of *s2, 51 * the length of *s1 is returned. 52 */ 53 int 54 isprefix(s1, s2) 55 register char *s1, *s2; 56 { 57 char *os1; 58 register char c1, c2; 59 60 if (*s1 == '\0') 61 return(-1); 62 os1 = s1; 63 c1 = *s1; 64 c2 = *s2; 65 while (LOWER(c1) == LOWER(c2)) { 66 if (c1 == '\0') 67 break; 68 c1 = *++s1; 69 c2 = *++s2; 70 } 71 return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1))); 72 } 73 74 static char *ambiguous; /* special return value for command routines */ 75 76 char ** 77 genget(name, table, stlen) 78 char *name; /* name to match */ 79 char **table; /* name entry in table */ 80 int stlen; 81 { 82 register char **c, **found; 83 register int n; 84 85 if (name == 0) 86 return 0; 87 88 found = 0; 89 for (c = table; *c != 0; c = (char **)((char *)c + stlen)) { 90 if ((n = isprefix(name, *c)) == 0) 91 continue; 92 if (n < 0) /* exact match */ 93 return(c); 94 if (found) 95 return(&ambiguous); 96 found = c; 97 } 98 return(found); 99 } 100 101 /* 102 * Function call version of Ambiguous() 103 */ 104 int 105 Ambiguous(s) 106 char **s; 107 { 108 return(s == &ambiguous); 109 } 110