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.\"	$OpenBSD: lsearch.3,v 1.9 2009/02/10 21:47:56 jmc Exp $
.\"
.\" Copyright (c) 1989, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
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.\"    notice, this list of conditions and the following disclaimer.
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.\" 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.
.\"
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" SUCH DAMAGE.
.\"
.\"     @(#)lsearch.3	8.1 (Berkeley) 6/4/93
.\"
.Dd $Mdocdate: February 10 2009 $
.Dt LSEARCH 3
.Os
.Sh NAME
.Nm lsearch ,
.Nm lfind
.Nd linear searching routines
.Sh SYNOPSIS
.Fd #include <search.h>
.Ft char *
.Fn lsearch "const void *key" "const void *base" "size_t *nelp" \
    "size_t width" "int (*compar)(const void *, const void *)"
.Ft char *
.Fn lfind "const void *key" "const void *base" "size_t *nelp" \
    "size_t width" "int (*compar)(const void *, const void *)"
.Sh DESCRIPTION
The functions
.Fn lsearch
and
.Fn lfind
provide basic linear searching functionality.
.Pp
.Fa base
is the pointer to the beginning of an array.
The argument
.Fa nelp
is the current number of elements in the array, where each element
is
.Fa width
bytes long.
The
.Fa compar
function
is a comparison routine which is used to compare two elements.
It takes two arguments which point to the
.Fa key
object and to an array member, in that order, and must return an integer
less than, equivalent to, or greater than zero if the
.Fa key
object is considered, respectively, to be less than, equal to, or greater
than the array member.
.Pp
The
.Fn lsearch
and
.Fn lfind
functions
return a pointer into the array referenced by
.Fa base
where
.Fa key
is located.
If
.Fa key
does not exist,
.Fn lfind
will return a null pointer and
.Fn lsearch
will add it to the array.
When an element is added to the array by
.Fn lsearch ,
the location referenced by the argument
.Fa nelp
is incremented by one.
.Sh SEE ALSO
.Xr bsearch 3 ,
.Xr db 3
.Sh STANDARDS
The
.Fn lsearch
and
.Fn lfind
functions conform to the
.St -p1003.1-2001
and
.St -xpg4.3
specifications.