genget.c revision 84305
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__FBSDID("$FreeBSD: head/contrib/telnet/libtelnet/genget.c 84305 2001-10-01 16:04:55Z markm $"); 36 37#ifndef lint 38#if 0 39static const char sccsid[] = "@(#)genget.c 8.2 (Berkeley) 5/30/95"; 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 */ 53int 54isprefix(char *s1, char *s2) 55{ 56 char *os1; 57 char c1, c2; 58 59 if (*s1 == '\0') 60 return(-1); 61 os1 = s1; 62 c1 = *s1; 63 c2 = *s2; 64 while (LOWER(c1) == LOWER(c2)) { 65 if (c1 == '\0') 66 break; 67 c1 = *++s1; 68 c2 = *++s2; 69 } 70 return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1))); 71} 72 73static char *ambiguous; /* special return value for command routines */ 74 75char ** 76genget(char *name, char **table, int stlen) 77{ 78 char **c, **found; 79 int n; 80 81 if (name == 0) 82 return 0; 83 84 found = 0; 85 for (c = table; *c != 0; c = (char **)((char *)c + stlen)) { 86 if ((n = isprefix(name, *c)) == 0) 87 continue; 88 if (n < 0) /* exact match */ 89 return(c); 90 if (found) 91 return(&ambiguous); 92 found = c; 93 } 94 return(found); 95} 96 97/* 98 * Function call version of Ambiguous() 99 */ 100int 101Ambiguous(char *s) 102{ 103 return((char **)s == &ambiguous); 104} 105