ffz(9) centos man page | unix.com

FFZ(9)							     Basic C Library Functions							    FFZ(9)

NAME
       ffz - find first zero bit in word

SYNOPSIS
       unsigned long ffz(unsigned long word);

ARGUMENTS
       word
	   The word to search

DESCRIPTION
       Undefined if no zero exists, so code should check against ~0UL first.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014								    FFZ(9)