minix/lib/libc/stdlib/lsearch.c

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/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Roger L. Snyder.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)lsearch.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: lsearch.c,v 1.7 2012/06/25 22:32:45 abs Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <assert.h>
#include <errno.h>
#include <string.h>
#include <search.h>
typedef int (*cmp_fn_t)(const void *, const void *);
static void *linear_base(const void *, void *, size_t *, size_t,
cmp_fn_t, int);
void *
lsearch(const void *key, void *base, size_t *nelp, size_t width,
cmp_fn_t compar)
{
_DIAGASSERT(key != NULL);
_DIAGASSERT(base != NULL);
_DIAGASSERT(compar != NULL);
return(linear_base(key, base, nelp, width, compar, 1));
}
void *
lfind(const void *key, const void *base, size_t *nelp, size_t width,
cmp_fn_t compar)
{
_DIAGASSERT(key != NULL);
_DIAGASSERT(base != NULL);
_DIAGASSERT(compar != NULL);
return(linear_base(key, __UNCONST(base), nelp, width, compar, 0));
}
static void *
linear_base(const void *key, void *base, size_t *nelp, size_t width,
cmp_fn_t compar, int add_flag)
{
char *element, *end;
_DIAGASSERT(key != NULL);
_DIAGASSERT(base != NULL);
_DIAGASSERT(compar != NULL);
end = (char *)base + *nelp * width;
for (element = (char *)base; element < end; element += width)
if (!compar(element, key)) /* key found */
return element;
if (!add_flag) /* key not found */
return(NULL);
/*
* The UNIX System User's Manual, 1986 edition claims that
* a NULL pointer is returned by lsearch with errno set
* appropriately, if there is not enough room in the table
* to add a new item. This can't be done as none of these
* routines have any method of determining the size of the
* table. This comment isn't in the 1986-87 System V
* manual.
*/
++*nelp;
memcpy(end, key, width);
return end;
}