1.\" $OpenBSD: lsearch.3,v 1.11 2014/07/18 07:25:26 matthew Exp $ 2.\" 3.\" Copyright (c) 1989, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)lsearch.3 8.1 (Berkeley) 6/4/93 31.\" 32.Dd $Mdocdate: July 18 2014 $ 33.Dt LSEARCH 3 34.Os 35.Sh NAME 36.Nm lsearch , 37.Nm lfind 38.Nd linear searching routines 39.Sh SYNOPSIS 40.In search.h 41.Ft char * 42.Fn lsearch "const void *key" "void *base" "size_t *nelp" \ 43 "size_t width" "int (*compar)(const void *, const void *)" 44.Ft char * 45.Fn lfind "const void *key" "const void *base" "size_t *nelp" \ 46 "size_t width" "int (*compar)(const void *, const void *)" 47.Sh DESCRIPTION 48The functions 49.Fn lsearch 50and 51.Fn lfind 52provide basic linear searching functionality. 53.Pp 54.Fa base 55is the pointer to the beginning of an array. 56The argument 57.Fa nelp 58is the current number of elements in the array, where each element 59is 60.Fa width 61bytes long. 62The 63.Fa compar 64function 65is a comparison routine which is used to compare two elements. 66It takes two arguments which point to the 67.Fa key 68object and to an array member, in that order, and must return an integer 69less than, equivalent to, or greater than zero if the 70.Fa key 71object is considered, respectively, to be less than, equal to, or greater 72than the array member. 73.Pp 74The 75.Fn lsearch 76and 77.Fn lfind 78functions 79return a pointer into the array referenced by 80.Fa base 81where 82.Fa key 83is located. 84If 85.Fa key 86does not exist, 87.Fn lfind 88will return a null pointer and 89.Fn lsearch 90will add it to the array. 91When an element is added to the array by 92.Fn lsearch , 93the location referenced by the argument 94.Fa nelp 95is incremented by one. 96.Sh SEE ALSO 97.Xr bsearch 3 , 98.Xr db 3 99.Sh STANDARDS 100The 101.Fn lsearch 102and 103.Fn lfind 104functions conform to the 105.St -p1003.1-2001 106and 107.St -xpg4.3 108specifications. 109