BSEARCH(3) FreeBSD Library Functions Manual BSEARCH(3)


bsearchbinary search of a sorted table


Standard C Library (libc, -lc)


#include < stdlib.h>

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


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

The contents of the array should be in ascending sorted order according to the comparison function referenced by compar. The compar routine is expected to have two arguments which point to the key object and to an array member, in that order, and should return an integer less than, equal to, or greater than zero if the key object is found, respectively, to be less than, to match, or be greater than the array member. See the int_compare sample function in qsort(3) for a comparison function that is also compatible with bsearch().


The bsearch() function returns a pointer to a matching member of the array, or a null pointer if no match is found. If two members compare as equal, which member is matched is unspecified.


The bsearch() function conforms to ISO/IEC 9899:1990 (“ISO C90”).
February 22, 2013 FreeBSD