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 /* from: static char sccsid[] = "@(#)genget.c 8.1 (Berkeley) 6/4/93"; */ 36 static char *rcsid = "$Id: genget.c,v 1.3 1994/02/25 02:52:59 cgd Exp $"; 37 #endif /* not lint */ 38 39 40 #include <ctype.h> 41 42 #define LOWER(x) (isupper(x) ? tolower(x) : (x)) 43 /* 44 * The prefix function returns 0 if *s1 is not a prefix 45 * of *s2. If *s1 exactly matches *s2, the negative of 46 * the length is returned. If *s1 is a prefix of *s2, 47 * the length of *s1 is returned. 48 */ 49 int 50 isprefix(s1, s2) 51 register char *s1, *s2; 52 { 53 register int n = 0; 54 char *os1; 55 register char c1, c2; 56 57 if (*s1 == '\0') 58 return(-1); 59 os1 = s1; 60 c1 = *s1; 61 c2 = *s2; 62 while (LOWER(c1) == LOWER(c2)) { 63 if (c1 == '\0') 64 break; 65 c1 = *++s1; 66 c2 = *++s2; 67 } 68 return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1))); 69 } 70 71 static char *ambiguous; /* special return value for command routines */ 72 73 char ** 74 genget(name, table, stlen) 75 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(s) 103 char *s; 104 { 105 return((char **)s == &ambiguous); 106 } 107