acl_extended_file(3) — Linux manual page


ACL_EXTENDED_FILE(3)  BSD Library Functions Manual  ACL_EXTENDED_FILE(3)

NAME         top

     acl_extended_file, acl_extended_file_nofollow — test for
     information in ACLs by file name

LIBRARY         top

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

SYNOPSIS         top

     #include <sys/types.h>
     #include <acl/libacl.h>

     acl_extended_file(const char *path_p);

     acl_extended_file_nofollow(const char *path_p);

DESCRIPTION         top

     The acl_extended_file() function returns 1 if the file or directory
     referred to by the argument path_p is associated with an extended
     access ACL, or if the directory referred to by path_p is associated
     with a default ACL. The function returns 0 if the file has neither
     an extended access ACL nor a default ACL.

     An extended ACL is an ACL that contains entries other than the
     three required entries of tag types ACL_USER_OBJ, ACL_GROUP_OBJ and
     ACL_OTHER.  If the result of the acl_extended_file() function for a
     file object is 0, then ACLs define no discretionary access rights
     other than those already defined by the traditional file permission

     Access to the file object may be further restricted by other
     mechanisms, such as Mandatory Access Control schemes. The access(2)
     system call can be used to check whether a given type of access to
     a file object would be granted.

     acl_extended_file_nofollow() is identical to acl_extended_file(),
     except in the case of a symbolic link, where the link itself is
     interrogated, not the file that it refers to.  Since symbolic links
     have no ACL themselves, the operation is supposed to fail on them.

RETURN VALUE         top

     If successful, the acl_extended_file() function returns 1 if the
     file object referred to by path_p has an extended access ACL or a
     default ACL, and 0 if the file object referred to by path_p has
     neither an extended access ACL nor a default ACL. Otherwise, the
     value -1 is returned and the global variable errno is set to
     indicate the error.

ERRORS         top

     If any of the following conditions occur, the acl_extended_file()
     function returns -1 and sets errno to the corresponding value:

     [EACCES]           Search permission is denied for a component of
                        the path prefix.

     [ENAMETOOLONG]     The length of the argument path_p is too long.

     [ENOENT]           The named object does not exist or the argument
                        path_p points to an empty string.

     [ENOTDIR]          A component of the path prefix is not a

     [ENOTSUP]          The file system on which the file identified by
                        path_p is located does not support ACLs, or ACLs
                        are disabled.

STANDARDS         top

     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         top

     access(2), acl_get_file(3), acl(5)

AUTHOR         top

     Written 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 2023-06-23.  (At that
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Linux ACL                    March 23, 2002                    Linux ACL