acl_get_fd(3) — Linux manual page


ACL_GET_FD(3)            Library Functions Manual          ACL_GET_FD(3)

NAME         top

       acl_get_fd — get an ACL by file descriptor

LIBRARY         top

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

SYNOPSIS         top

       <sys/types.h> <sys/acl.h> acl_t acl_get_fd(int fd)

DESCRIPTION         top

       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         top

       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         top

       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

       [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.

STANDARDS         top

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

SEE ALSO         top

       acl_free(3), acl_get_entry(3), acl_get_file(3), acl_set_fd(3),

AUTHOR         top

       Derived from the FreeBSD manual pages written by Robert N M
       Watson <>, and adapted for Linux by Andreas
       Gruenbacher <>.

COLOPHON         top

       This page is part of the acl (manipulating access control lists)
       project.  Information about the project can be found at  If you have a bug
       report for this manual page, see
       ⟨⟩.  This page was
       obtained from the project's upstream Git repository
       ⟨git://⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2023-12-01.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
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       (which is not part of the original manual page), send a mail to

Linux ACL                    March 23, 2002                ACL_GET_FD(3)