acl_get_fd(3)

acl_get_fd3

Get an acl by file descriptor

Usage

#include <sys/types.h>

#include <sys/acl.h>

acl_t

acl_get_fd(int fd);

Library

Linux Access Control Lists library (libacl, -lacl).

Overview

The acl_get_fd() function retrieves the access ACL associated with the file referred to by fd. The ACL is placed into working storage and acl_get_fd() returns a pointer to that storage.

In order to read an ACL from an object, a process must have read access to the object's attributes.

This function may cause memory to be allocated. The caller should free any releasable memory, when the new ACL is no longer required, by calling acl_free(3) with the (void*)acl_t returned by acl_get_fd() as an argument.

Return value

On success, this function shall return a pointer to the working storage. On error, a value of (acl_t)NULL shall be returned, and errno is set appropriately.

Errors

If any of the following conditions occur, the acl_get_fd() function returns a value of (acl_t)NULL and sets errno to the corresponding value:

[EBADF]

The fd argument is not a valid file descriptor.

[ENOMEM]

The ACL working storage requires more memory than is allowed by the hardware or system-imposed memory management constraints.

[ENOTSUP]

The file system on which the file identified by fd is located does not support ACLs, or ACLs are disabled.

Releases

13 releases since Debian 3.0 (Woody); the text changed 4 times.

  1. 3.0
  2. 3.1
  3. 4.0–5.0
  4. 6.0–10
  5. 11–Arch

Standards

IEEE Std 1003.1e draft 17 (“POSIX.1e”, abandoned)

Author

Derived from the FreeBSD manual pages written by Robert N M Watson ⟨[email protected]⟩, and adapted for Linux by Andreas Gruenbacher ⟨[email protected]⟩.

From acl 2.4.0-1 in Arch Linux 2026-11-01. Parsed by carta from the page's mdoc source.