ffsl(3) [osx man page]

FFS(3)							   BSD Library Functions Manual 						    FFS(3)

NAME

     ffs, ffsl, fls, flsl -- find first or last bit set in a bit string

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <strings.h>

     int
     ffs(int i);

     int
     ffsl(long i);

     int
     fls(int i);

     int
     flsl(long i);

DESCRIPTION

     The ffs() and ffsl() functions find the first bit set in i and return the index of that bit.

     The fls() and flsl() functions find the last bit set in i and return the index of that bit.

     Bits are numbered starting from 1, starting at the right-most (least significant) bit.  A return value of zero from any of these functions
     means that the argument was zero.

SEE ALSO

     bitstring(3)

HISTORY

     The ffs() function appeared in 4.3BSD.  Its prototype existed previously in <string.h> before it was moved to <strings.h> for IEEE Std
     1003.1-2001 (``POSIX.1'') compliance.

     The ffsl(), fls(), and flsl() functions appeared in FreeBSD 5.3.

BSD
								 January 13, 2004							       BSD

FFS(3)							     Linux Programmer's Manual							    FFS(3)

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

       This  page is part of release 3.25 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/.

GNU
								    2009-08-27								    FFS(3)