1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Roger L. Snyder. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 #if defined(LIBC_SCCS) && !defined(lint) 35 #if 0 36 static char sccsid[] = "@(#)lsearch.c 8.1 (Berkeley) 6/4/93"; 37 #else 38 __RCSID("$NetBSD: lsearch.c,v 1.6 2012/03/20 16:38:44 matt Exp $"); 39 #endif 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include <sys/types.h> 43 44 #include <assert.h> 45 #include <errno.h> 46 #include <string.h> 47 #include <search.h> 48 49 typedef int (*cmp_fn_t)(const void *, const void *); 50 static void *linear_base(const void *, void *, size_t *, size_t, 51 cmp_fn_t, int); 52 53 void * 54 lsearch(key, base, nelp, width, compar) 55 const void *key; 56 void *base; 57 size_t *nelp, width; 58 cmp_fn_t compar; 59 { 60 61 _DIAGASSERT(key != NULL); 62 _DIAGASSERT(base != NULL); 63 _DIAGASSERT(compar != NULL); 64 65 return(linear_base(key, base, nelp, width, compar, 1)); 66 } 67 68 void * 69 lfind(key, base, nelp, width, compar) 70 const void *key, *base; 71 size_t *nelp, width; 72 cmp_fn_t compar; 73 { 74 75 _DIAGASSERT(key != NULL); 76 _DIAGASSERT(base != NULL); 77 _DIAGASSERT(compar != NULL); 78 79 return(linear_base(key, __UNCONST(base), nelp, width, compar, 0)); 80 } 81 82 static void * 83 linear_base(const void *key, void *base, size_t *nelp, size_t width, 84 cmp_fn_t compar, int add_flag) 85 { 86 char *element, *end; 87 88 _DIAGASSERT(key != NULL); 89 _DIAGASSERT(base != NULL); 90 _DIAGASSERT(compar != NULL); 91 92 end = (char *)base + *nelp * width; 93 for (element = (char *)base; element < end; element += width) 94 if (!compar(element, key)) /* key found */ 95 return element; 96 97 if (!add_flag) /* key not found */ 98 return(NULL); 99 100 /* 101 * The UNIX System User's Manual, 1986 edition claims that 102 * a NULL pointer is returned by lsearch with errno set 103 * appropriately, if there is not enough room in the table 104 * to add a new item. This can't be done as none of these 105 * routines have any method of determining the size of the 106 * table. This comment isn't in the 1986-87 System V 107 * manual. 108 */ 109 ++*nelp; 110 memcpy(end, key, width); 111 return end; 112 } 113