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 * @(#)genget.c 8.2 (Berkeley) 5/30/95 30 * $FreeBSD: src/crypto/telnet/libtelnet/genget.c,v 1.2.8.2 2002/04/13 10:59:07 markm Exp $ 31 */ 32 33 #include <sys/_null.h> 34 #include <ctype.h> 35 36 #include "misc-proto.h" 37 38 #define LOWER(x) (isupper(x) ? tolower(x) : (x)) 39 /* 40 * The prefix function returns 0 if *s1 is not a prefix 41 * of *s2. If *s1 exactly matches *s2, the negative of 42 * the length is returned. If *s1 is a prefix of *s2, 43 * the length of *s1 is returned. 44 */ 45 int 46 isprefix(char *s1, const char *s2) 47 { 48 char *os1; 49 char c1, c2; 50 51 if (*s1 == '\0') 52 return(-1); 53 os1 = s1; 54 c1 = *s1; 55 c2 = *s2; 56 while (LOWER(c1) == LOWER(c2)) { 57 if (c1 == '\0') 58 break; 59 c1 = *++s1; 60 c2 = *++s2; 61 } 62 return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1))); 63 } 64 65 static char *ambiguous; /* special return value for command routines */ 66 67 char ** 68 genget(char *name, char **table, int stlen) 69 { 70 char **c, **found; 71 int n; 72 73 if (name == NULL) 74 return 0; 75 76 found = NULL; 77 for (c = table; *c != NULL; c = (char **)((char *)c + stlen)) { 78 if ((n = isprefix(name, *c)) == 0) 79 continue; 80 if (n < 0) /* exact match */ 81 return(c); 82 if (found) 83 return(&ambiguous); 84 found = c; 85 } 86 return(found); 87 } 88 89 /* 90 * Function call version of Ambiguous() 91 */ 92 int 93 Ambiguous(char **s) 94 { 95 return(s == &ambiguous); 96 } 97