---
name: "__ffs"
section: "9"
platform: "linux"
package: "linux-manual-4.9"
version: "4.9.228-1"
release: "Debian 9 (Stretch)"
platforms: ["linux"]
url: "https://new.carta.tech/__ffs"
---

# \_\_ffs(9)

find first set bit in word

## NAME

\_\_ffs - find first set bit in word

## SYNOPSIS

**unsigned long \_\_ffs(unsigned long** *word***);**

## ARGUMENTS

*word*

The word to search

## DESCRIPTION

Undefined if no bit exists, so code should check against 0 first.

## COPYRIGHT