---
name: "acl_equiv_mode"
section: "3"
platform: "linux"
package: "acl"
version: "2.4.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/acl_equiv_mode"
---

# acl\_equiv\_mode(3)

check for an equivalent ACL

## NAME

**acl\_equiv\_mode** – check for an equivalent ACL

## LIBRARY

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

## SYNOPSIS

**#include \<sys/types.h\>**

**#include \<acl/libacl.h\>**

*int*\

**acl\_equiv\_mode**(*acl\_t acl*, *mode\_t \*mode\_p*);

## DESCRIPTION

The **acl\_equiv\_mode**() function checks if the ACL pointed to by the argument *acl* contains only the required ACL entries of tag types ACL\_USER\_OBJ, ACL\_GROUP\_OBJ, and ACL\_OTHER, and contains no permissions other that ACL\_READ, ACL\_WRITE or ACL\_EXECUTE. If the ACL has this form, it can can be fully represented with the traditional file permission bits, and is considered equivalent with the traditional file permission bits.

If *acl* is an equivalent ACL and the pointer *mode\_p* is not NULL, the value pointed to by *mode\_p* is set to the value that defines the same owner, group and other permissions as contained in the ACL.

## RETURN VALUE

On success, this function returns the value 0 if *acl* is an equivalent ACL, and the value 1 if *acl* is not an equivalent ACL. On error, the value -1 is returned, and *errno* is set appropriately.

## ERRORS

If any of the following conditions occur, the **acl\_equiv\_mode**() function returns the value -1 and sets *errno* to the corresponding value:

- \[EINVAL\]

  The argument *acl* is not a valid pointer to an ACL.

## STANDARDS

This is a non-portable, Linux specific extension to the ACL manipulation functions defined in IEEE Std 1003.1e draft 17 (“POSIX.1e”, abandoned).

## SEE ALSO

[acl\_from\_mode(3)](/acl_from_mode/3.md), [acl(5)](/acl/5.md)

## AUTHOR

Written by Andreas Gruenbacher ⟨andreas.gruenbacher@gmail.com⟩.