| flsll, ffs, ffsl, ffsll, fls, flsl(3) | find first or last bit set in a bit string |
| ffs, ffsl, ffsll, fls, flsl, flsll(3) | find first or last bit set in a bit string |
| ffsl, ffs, ffsll, fls, flsl, flsll(3) | find first or last bit set in a bit string |
| ffsll, ffs, ffsl, fls, flsl, flsll(3) | find first or last bit set in a bit string |
| fls, ffs, ffsl, ffsll, flsl, flsll(3) | find first or last bit set in a bit string |
| flsl, ffs, ffsl, ffsll, fls, flsll(3) | find first or last bit set in a bit string |
| FFS(3) | MidnightBSD Library Functions Manual | FFS(3) |
ffs, ffsl,
ffsll, fls,
flsl, flsll —
find first or last bit set in a bit string
Standard C Library (libc, -lc)
#include
<strings.h>
int
ffs(int
value);
int
ffsl(long
value);
int
ffsll(long
long value);
int
fls(int
value);
int
flsl(long
value);
int
flsll(long
long value);
The
ffs(),
ffsl()
and
ffsll()
functions find the first (least significant) bit set in
value and return the index of that bit.
The
fls(),
flsl()
and
flsll()
functions find the last (most significant) 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.
The ffs() function appeared in
4.3BSD. Its prototype existed previously 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 7.1.
| October 17, 2015 | midnightbsd-3.1 |