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FFS(3)			    Library Functions Manual			FFS(3)

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

LIBRARY
       Standard	C Library (libc, -lc)

SYNOPSIS
       #include	<strings.h>

       int
       ffs(int value);

       int
       ffsl(long value);

       int

       int
       ffsll(long long value);

       fls(int value);

       int
       flsl(long value);

       int
       flsll(long long value);

DESCRIPTION
       The ffs(), ffsl() and ffsll() functions find the	first bit set  (begin-
       ning  with  the least significant bit) in value and return the index of
       that bit.

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

       Bits  are numbered starting at 1	(the 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	previ-
       ously 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.  The
       ffsll() and flsll() functions appeared in FreeBSD 8.0.

GNU			       October 26, 2008				FFS(3)
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | SEE ALSO | HISTORY

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