#include <strings.h>int ffs(int i);#define _GNU_SOURCE #include <string.h>int ffsl(long int i);int ffsll(long long int i);
DESCRIPTION
The
ffs()
function returns the position of the first
(least significant) bit set in the word i.
The least significant bit is position 1 and the
most significant position is, for example, 32 or 64.
The functions
ffsll()
and
ffsl()
do the same but take
arguments of possibly different size.
RETURN VALUE
These functions return the position of the first bit set,
or 0 if no bits are set in
i.
This page is part of release 3.14 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.
