1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Chris Torek. 6.\" %sccs.include.redist.man% 7.\" 8.\" @(#)ffs.3 8.2 (Berkeley) 04/19/94 9.\" 10.Dd 11.Dt FFS 3 12.Os 13.Sh NAME 14.Nm ffs 15.Nd find first bit set in a bit string 16.Sh SYNOPSIS 17.Fd #include <string.h> 18.Ft int 19.Fn ffs "int value" 20.Sh DESCRIPTION 21The 22.Fn ffs 23function finds the first bit set in 24.Fa value 25and returns the index of that bit. 26Bits are numbered starting from 1, starting at the right-most 27bit. 28A return value of 0 means that the argument was zero. 29.Sh SEE ALSO 30.Xr bitstring 3 31.Sh HISTORY 32The 33.Fn ffs 34function appeared in 35.Bx 4.3 . 36