GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages
FFS(3) FreeBSD 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.

bitstring(3), bitset(9)

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 FreeBSD 13.1-RELEASE

Search for    or go to Top of page |  Section 3 |  Main Index

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with ManDoc.