FFS(3) NetBSD Library Functions Manual FFS(3)
ffs -- find first bit set in a bit string
Standard C Library (libc, -lc)
#include <strings.h> int ffs(int value);
The ffs() function finds the first bit set in value and returns the index of that bit. Bits are numbered starting from 1, starting at the right- most bit. A return value of 0 means that the argument was zero.
bitstring(3), ffs32(3), popcount(3)
The ffs() function conforms to IEEE Std 1003.1-2001 (``POSIX.1'').
The ffs() function appeared in 4.3BSD. The prototype for it existed pre- viously in the <string.h> header before it was moved to <strings.h> for POSIX compliance. NetBSD 9.0 April 28, 2010 NetBSD 9.0
You can also request any man page by name and (optionally) by section: