---
name: "feature_present"
section: "3"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/feature_present"
---

# feature\_present(3)

query presence of a kernel feature

## NAME

**feature\_present** – query presence of a kernel feature

## LIBRARY

Standard C Library (libc, -lc)

## SYNOPSIS

**#include \<unistd.h\>**

*int*\

**feature\_present**(*const char \*feature*);

## DESCRIPTION

The **feature\_present**() function provides a method for an application to determine if a specific kernel feature is present in the currently running kernel. The *feature* argument specifies the name of the feature to check. The **feature\_present**() function will return 1 if the specified feature is present, otherwise it will return 0. If the **feature\_present**() function is not able to determine the presence of *feature* due to an internal error it will return 0.

## RETURN VALUES

If *feature* is present then 1 is returned; otherwise 0 is returned.

## SEE ALSO

[sysconf(3)](/sysconf/3.md), [sysctl(3)](/sysctl/3.md)

## HISTORY

The **feature\_present**() function first appeared in FreeBSD 8.0.