NAME
ffs, ffsl, ffsll - find first bit set in a word
SYNOPSIS
#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.
CONFORMING TO
ffs():4.3BSD,POSIX.1-2001. The ffsl() and ffsll() are glibc
extensions.
NOTES
BSD systems have a prototype in <string.h>.
SEE ALSO
memchr(3), feature_test_macros(7)
COLOPHON
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be found at http://www.kernel.org/doc/man-pages/.