diff options
Diffstat (limited to 'lib/libc/string/ffs.3')
| -rw-r--r-- | lib/libc/string/ffs.3 | 41 |
1 files changed, 35 insertions, 6 deletions
diff --git a/lib/libc/string/ffs.3 b/lib/libc/string/ffs.3 index 5b5fb6f..cb9c6cc 100644 --- a/lib/libc/string/ffs.3 +++ b/lib/libc/string/ffs.3 @@ -38,23 +38,44 @@ .Dt FFS 3 .Os .Sh NAME -.Nm ffs -.Nd find first bit set in a bit string +.Nm ffs , +.Nm ffsl , +.Nm fls , +.Nm flsl +.Nd find first or last bit set in a bit string .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In strings.h .Ft int .Fn ffs "int value" +.Ft int +.Fn ffsl "long value" +.Ft int +.Fn fls "int value" +.Ft int +.Fn flsl "long value" .Sh DESCRIPTION The .Fn ffs -function finds the first bit set in +and +.Fn ffsl +functions find the first bit set in .Fa value -and returns the index of that bit. +and return the index of that bit. +.Pp +The +.Fn fls +and +.Fn flsl +functions find the last bit set in +.Fa value +and return the index of that bit. +.Pp Bits are numbered starting from 1, starting at the right-most -bit. -A return value of 0 means that the argument was zero. +(least significant) bit. +A return value of zero from any of these functions means that the +argument was zero. .Sh SEE ALSO .Xr bitstring 3 .Sh HISTORY @@ -69,3 +90,11 @@ before it was moved to for .St -p1003.1-2001 compliance. +.Pp +The +.Fn ffsl , +.Fn fls +and +.Fn flsl +functions appeared in +.Fx 5.3 . |
