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 #if defined(LIBC_SCCS) && !defined(lint) 34 static char sccsid[] = "@(#)lsearch.c 8.1 (Berkeley) 6/4/93"; 35 #endif /* LIBC_SCCS and not lint */ 36 37 #include <sys/types.h> 38 #include <string.h> 39 #include <search.h> 40 41 typedef int (*cmp_fn_t)(const void *, const void *); 42 static void *linear_base(const void *, const void *, size_t *, size_t, 43 cmp_fn_t, int); 44 45 void * 46 lsearch(const void *key, const void *base, size_t *nelp, size_t width, 47 cmp_fn_t compar) 48 { 49 50 return(linear_base(key, base, nelp, width, compar, 1)); 51 } 52 53 void * 54 lfind(const void *key, const void *base, size_t *nelp, size_t width, 55 cmp_fn_t compar) 56 { 57 return(linear_base(key, base, nelp, width, compar, 0)); 58 } 59 60 static void * 61 linear_base(const void *key, const void *base, size_t *nelp, size_t width, 62 cmp_fn_t compar, int add_flag) 63 { 64 const char *element, *end; 65 66 end = (const char *)base + *nelp * width; 67 for (element = base; element < end; element += width) 68 if (!compar(key, element)) /* key found */ 69 return((void *)element); 70 71 if (!add_flag) /* key not found */ 72 return(NULL); 73 74 /* 75 * The UNIX System User's Manual, 1986 edition claims that 76 * a NULL pointer is returned by lsearch with errno set 77 * appropriately, if there is not enough room in the table 78 * to add a new item. This can't be done as none of these 79 * routines have any method of determining the size of the 80 * table. This comment isn't in the 1986-87 System V 81 * manual. 82 */ 83 ++*nelp; 84 memcpy((void *)end, key, width); 85 return((void *)end); 86 } 87