107 lines
3.3 KiB
Groff
107 lines
3.3 KiB
Groff
.\" $OpenBSD: lsearch.3,v 1.14 2015/11/30 17:03:05 jmc Exp $
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.\"
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.\" Copyright (c) 1989, 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)lsearch.3 8.1 (Berkeley) 6/4/93
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.\"
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.Dd $Mdocdate: November 30 2015 $
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.Dt LSEARCH 3
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.Os
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.Sh NAME
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.Nm lsearch ,
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.Nm lfind
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.Nd linear searching routines
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.Sh SYNOPSIS
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.In search.h
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.Ft void *
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.Fn lsearch "const void *key" "void *base" "size_t *nelp" \
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"size_t width" "int (*compar)(const void *, const void *)"
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.Ft void *
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.Fn lfind "const void *key" "const void *base" "size_t *nelp" \
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"size_t width" "int (*compar)(const void *, const void *)"
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.Sh DESCRIPTION
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The functions
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.Fn lsearch
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and
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.Fn lfind
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provide basic linear searching functionality.
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.Pp
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.Fa base
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is the pointer to the beginning of an array.
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The argument
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.Fa nelp
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is the current number of elements in the array, where each element
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is
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.Fa width
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bytes long.
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The
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.Fa compar
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function
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is a comparison routine which is used to compare two elements.
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It takes two arguments which point to the
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.Fa key
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object and to an array member, in that order, and must return an integer
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less than, equivalent to, or greater than zero if the
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.Fa key
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object is considered, respectively, to be less than, equal to, or greater
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than the array member.
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.Pp
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The
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.Fn lsearch
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and
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.Fn lfind
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functions
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return a pointer into the array referenced by
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.Fa base
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where
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.Fa key
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is located.
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If
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.Fa key
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does not exist,
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.Fn lfind
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will return a null pointer and
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.Fn lsearch
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will add it to the array.
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When an element is added to the array by
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.Fn lsearch ,
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the location referenced by the argument
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.Fa nelp
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is incremented by one.
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.Sh SEE ALSO
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.Xr bsearch 3 ,
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.Xr dbopen 3
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.Sh STANDARDS
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The
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.Fn lsearch
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and
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.Fn lfind
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functions conform to the X/Open System Interfaces option of the
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.St -p1003.1-2008
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specification.
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