1993-03-21 12:45:37 +03:00
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.\" Copyright (c) 1990, 1991 The Regents of the University of California.
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.\" All rights reserved.
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.\"
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.\" This code is derived from software contributed to Berkeley by
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.\" the American National Standards Committee X3, on Information
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.\" Processing Systems.
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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. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by the University of
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.\" California, Berkeley and its contributors.
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.\" 4. 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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1993-08-01 11:42:49 +04:00
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.\" from: @(#)bsearch.3 5.6 (Berkeley) 6/29/91
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1994-01-11 02:32:20 +03:00
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.\" $Id: bsearch.3,v 1.3 1994/01/10 23:36:40 jtc Exp $
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1993-03-21 12:45:37 +03:00
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.\"
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.Dd June 29, 1991
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.Dt BSEARCH 3
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.Os
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.Sh NAME
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.Nm bsearch
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.Nd binary search of a sorted table
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.Sh SYNOPSIS
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.Fd #include <stdlib.h>
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.Ft void *
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.Fn bsearch "const void *key" "const void *base" "size_t nmemb" "size_t size" "int (*compar) (const void *, const void *)"
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.Sh DESCRIPTION
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The
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.Fn bsearch
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function searches an array of
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.Fa nmemb
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1994-01-11 02:32:20 +03:00
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objects, the initial member of which is
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1993-03-21 12:45:37 +03:00
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pointed to by
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.Fa base ,
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for a member that matches the object pointed to by
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.Fa key .
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The size of each member of the array is specified by
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.Fa size .
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.Pp
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The contents of the array should be in ascending sorted order according
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to the comparison function referenced by
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.Fa compar .
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The
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.Fa compar
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routine
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is expected to have two
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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 should return an integer
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less than, equal to, or greater than zero if the
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.Fa key
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object is found, respectively, to be less than, to match, or be
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greater than the array member.
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.Sh RETURN VALUES
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The
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.Fn bsearch
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function returns a pointer to a matching member of the array, or a null
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pointer if no match is found.
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If two members compare as equal, which member is matched is unspecified.
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.Sh SEE ALSO
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.Xr db 3 ,
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.Xr lsearch 3 ,
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.Xr qsort 3 ,
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.\" .Xr tsearch 3
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.Sh STANDARDS
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The
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.Fn bsearch
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function conforms to
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.St -ansiC .
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