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FFS(3) NetBSD Library Functions Manual FFS(3)
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ffs -- find first bit set in a bit string
Standard C Library (libc, -lc)
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
NetBSD 10.99 April 28, 2010 NetBSD 10.99