---
name: "acl_get_fd"
section: "3"
platform: "macos"
package: "Libc"
version: "1752.120.2"
release: "macOS 26.5"
platforms: ["linux", "freebsd", "macos"]
url: "https://new.carta.tech/acl_get_fd"
---

# acl\_get\_fd(3)

get an ACL for a file

## NAME

**acl\_get\_fd**, **acl\_get\_fd\_np**, **acl\_get\_file**, **acl\_get\_link\_np** – get an ACL for a file

## LIBRARY

Standard C Library (libc, -lc)

## SYNOPSIS

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

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

*acl\_t*\

**acl\_get\_fd**(*int fd*);

*acl\_t*\

**acl\_get\_fd\_np**(*int fd*, *acl\_type\_t type*);

*acl\_t*\

**acl\_get\_file**(*const char \*path\_p*, *acl\_type\_t type*);

*acl\_t*\

**acl\_get\_link\_np**(*const char \*path\_p*, *acl\_type\_t type*);

## DESCRIPTION

The **acl\_get\_fd**(), **acl\_get\_file**(), **acl\_get\_link\_np**(), and **acl\_get\_fd\_np**() each allow the retrieval of an ACL from a file. The **acl\_get\_fd**() is a POSIX.1e call that allows the retrieval of an ACL of type ACL\_TYPE\_ACCESS from a file descriptor. The **acl\_get\_fd\_np**() function is a non-portable form of **acl\_get\_fd**() that allows the retrieval of any type of ACL from a file descriptor. The **acl\_get\_file**() function is a POSIX.1e call that allows the retrieval of a specified type of ACL from a file by name; **acl\_get\_link\_np**() is a non-portable variation on **acl\_get\_file**() which does not follow a symlink if the target of the call is a symlink.

These functions 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)](/acl_free/3.md) with the *(void* *\*)acl\_t* as an argument.

The ACL in the working storage is an independent copy of the ACL associated with the object referred to by *fd*. The ACL in the working storage shall not participate in any access control decisions.

## RETURN VALUES

Upon successful completion, the function shall return a pointer to the ACL that was retrieved.  Otherwise, a value of *(acl\_t)NULL* shall be returned, and *errno* shall be set to indicate the error.

## ERRORS

If any of the following conditions occur, the **acl\_get\_fd**() function shall return a value of *(acl\_t)NULL* and set *errno* to the corresponding value:

- \[EACCES\]

  Search permission is denied for a component of the path prefix, or the object exists and the process does not have appropriate access rights.

- \[EBADF\]

  The *fd* argument is not a valid file descriptor.

- \[EINVAL\]

  The ACL type passed is invalid for this file object.

- \[ENAMETOOLONG\]

  A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.

- \[ENOENT\]

  The named object does not exist, or the *path\_p* argument points to an empty string.

- \[ENOMEM\]

  Insufficient memory available to fulfill request.

- \[EOPNOTSUPP\]

  The file system does not support ACL retrieval.

## SEE ALSO

[acl(3)](/acl/3.md), [acl\_free(3)](/acl_free/3.md), [acl\_get(3)](/acl_get/3.md), [acl\_set(3)](/acl_set/3.md), [posix1e(3)](/posix1e/3.md)

## STANDARDS

POSIX.1e is described in IEEE POSIX.1e draft 17. and development continues.

## AUTHORS

Michael Smith Robert N M Watson