NAME

ffs ffsl ffsll — find first set bit

SYNOPSIS

[XSI]
#include <strings.h>

int ffs(int i);
int ffsl(long i);
int ffsll(long long i);

DESCRIPTION

The ffs (), ffsl (), and ffsll () functions shall find the first bit set (beginning with the least significant bit) in i, and return the index of that bit. Bits are numbered starting at one (the least significant bit).

RETURN VALUE

The ffs (), ffsl (), and ffsll () functions shall return the index of the first bit set. If i is 0, then these functions shall return 0.

ERRORS

No errors are defined.

The following sections are informative.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

XBD <strings.h>

CHANGE HISTORY

First released in Issue 4, Version 2.

Issue 5

Moved from X/OPEN UNIX extension to BASE.

Issue 8

Austin Group Defect 617 is applied, adding ffsl () and ffsll ().

End of informative text.