.\" .\" Initial implementation: .\" Copyright (c) 2002 Robert Drehmel .\" All rights reserved. .\" .\" As long as the above copyright statement and this notice remain .\" unchanged, you can do what ever you want with this file. .\" .\" $FreeBSD: src/lib/libc/stdlib/lsearch.3,v 1.4 2002/12/19 09:40:24 ru Exp $ .\" .Dd October 11, 2002 .Dt LSEARCH 3 .Os .Sh NAME .Nm lsearch , .Nm lfind .Nd linear search and append .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In search.h .Ft "void *" .Fo lsearch .Fa "const void *key" "void *base" "size_t *nelp" "size_t width" .Fa "int \*[lp]*compar\*[rp]\*[lp]const void *, const void *\*[rp]" .Fc .Ft "void *" .Fo lfind .Fa "const void *key" "const void *base" "size_t *nelp" "size_t width" .Fa "int \*[lp]*compar\*[rp]\*[lp]const void *, const void *\*[rp]" .Fc .Sh DESCRIPTION The .Fn lsearch and .Fn lfind functions walk linearly through an array and compare each element with the one to be sought using a supplied comparison function. .Pp The .Fa key argument points to an element that matches the one that is searched. The array's address in memory is denoted by the .Fa base argument. The width of one element (i.e., the size as returned by .Fn sizeof ) is passed as the .Fa width argument. The number of valid elements contained in the array (not the number of elements the array has space reserved for) is given in the integer pointed to by .Fa nelp . The .Fa compar argument points to a function which compares its two arguments and returns zero if they are matching, and non-zero otherwise. .Pp If no matching element was found in the array, .Fn lsearch copies .Fa key into the position after the last element and increments the integer pointed to by .Fa nelp . .Sh RETURN VALUES The .Fn lsearch and .Fn lfind functions return a pointer to the first element found. If no element was found, .Fn lsearch returns a pointer to the newly added element, whereas .Fn lfind returns .Dv NULL . Both functions return .Dv NULL if an error occurs. .Sh SEE ALSO .Xr bsearch 3 , .Xr hsearch 3 , .Xr tsearch 3 .Sh HISTORY The .Fn lsearch and .Fn lfind functions appeared in .Bx 4.2 . In .Fx 5.0 , they reappeared conforming to .St -p1003.1-2001 . .Sh STANDARDS The .Fn lsearch and .Fn lfind functions conform to .St -p1003.1-2001 .