manpagez: man (manual) pages & more
man bsearch(3)
Home | html | info | man
bsearch(3)               BSD Library Functions Manual               bsearch(3)


NAME

     bsearch, bsearch_b -- binary search of a sorted table


SYNOPSIS

     #include <stdlib.h>

     void *
     bsearch(const void *key, const void *base, size_t nel, size_t width,
         int (*compar) (const void *, const void *));

     void *
     bsearch_b(const void *key, const void *base, size_t nel, size_t width,
         int (^compar) (const void *, const void *));


DESCRIPTION

     The bsearch() function searches an array of nel objects, the initial mem-
     ber of which is pointed to by base, for a member that matches the object
     pointed to by key.  The size (in bytes) of each member of the array is
     specified by width.

     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.  It should return an integer which is less
     than, equal to, or greater than zero if the key object is found, respec-
     tively, to be less than, to match, or be greater than the array member.

     The bsearch_b() function is like bsearch() except the callback compar is
     a block pointer instead of a function pointer.


RETURN VALUES

     The bsearch() and bsearch_b() functions returns a pointer to a matching
     member of the array, or a null pointer if no match is found.  If two mem-
     bers compare as equal, which member is matched is unspecified.


SEE ALSO

     db(3), lsearch(3), qsort(3)


STANDARDS

     The bsearch() function conforms to ISO/IEC 9899:1990 (``ISO C90'').

BSD                              May 20, 2008                              BSD

Mac OS X 10.8 - Generated Sun Aug 26 15:45:33 CDT 2012