NAME

bsearch − perform a binary search

SYNOPSIS

#include <stdlib.h>

void bsearch(const void ∗key,
const void ∗base,
            size_t nmemb,
size_t size,
int (∗compar)(const void ∗, const void ∗));

DESCRIPTION

The bsearch function searches an array of nmemb objects, the initial member of which is pointed to by base, for an element that matches the object pointed to by key.  The size of each element of the array is specified by size. 

The comparison function pointed to by compar is called with two arguments that point to the key object and to an array element, in that order.  Bsearch returns an integer less than, equal to, or greater than zero if the key object is considered, respectively, to be less than, to match, or to be greater than the array element.  The array shall consist of: all the elements that compare less than, all the objects that compare equal to and all the objects that compare greater than the key object, in that order. 

RETURN VALUE

Bsearch returns a pointer to a matching element of the array, or a null pointer if no match is found.  If two elements compare as equal, it is indeterminate which element will be matched. 

SEE ALSO

qsort(3)

STANDARDS

The bsearch function conforms to ANSI-C. 

7th Edition  —  August 1, 1992