---
name: "capng_apply_caps_fd"
section: "3"
platform: "linux"
package: "libcap-ng"
version: "0.9.6-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/capng_apply_caps_fd"
---

# capng\_apply\_caps\_fd(3)

write file-based capabilities to extended attributes

## NAME

capng\_apply\_caps\_fd - write file-based capabilities to extended attributes

## SYNOPSIS

**#include \<cap-ng.h\>**

int capng\_apply\_caps\_fd(int fd);

## DESCRIPTION

This function will write the file based capabilities to the extended attributes of the file that the descriptor was opened against. The bounding set is not included in file based capabilities operations. Note that this function will only work if compiled on a kernel that supports file based capabilities such as 2.6.2 6 and later.

## RETURN VALUE

This returns 0 on success, -1 if something besides a regular file is passed or the extended attribute operation fails, and -2 if the file capability data cannot be serialized.

## SEE ALSO

[**capng\_get\_caps\_fd**(3)](/capng_get_caps_fd/3.md), [**capabilities**(7)](/capabilities/7.md)

## AUTHOR

Steve Grubb