The Open Group Base Specifications Issue 6
IEEE Std 1003.1, 2004 Edition
Copyright © 2001-2004 The IEEE and The Open Group, All Rights reserved.

NAME

ffs - find first set bit

SYNOPSIS

[XSI] [Option Start] #include <strings.h>

int ffs(int i); [Option End]

DESCRIPTION

The ffs() function 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() function shall return the index of the first bit set. If i is 0, then ffs() 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

The Base Definitions volume of IEEE Std 1003.1-2001, <strings.h>

CHANGE HISTORY

First released in Issue 4, Version 2.

Issue 5

Moved from X/OPEN UNIX extension to BASE.

End of informative text.
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