ACL_EXTENDED_FILE(3) BSD Library Functions Manual ACL_EXTENDED_FILE(3)NAME
acl_extended_file, acl_extended_file_nofollow — test for information in
ACLs by file name
LIBRARY
Linux Access Control Lists library (libacl, -lacl).
SYNOPSIS
#include <sys/types.h>
#include <acl/libacl.h>
int
acl_extended_file(const char *path_p);
int
acl_extended_file_nofollow(const char *path_p);
DESCRIPTION
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 bits.
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 them‐
selves, the operation is supposed to fail on them.
RETURN VALUE
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
If any of the following conditions occur, the acl_extended_file() func‐
tion 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 directory.
[ENOTSUP] The file system on which the file identified by path_p
is located does not support ACLs, or ACLs are dis‐
abled.
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 ALSOaccess(2), acl_get_file(3), acl(5)AUTHOR
Written by Andreas Gruenbacher ⟨a.gruenbacher@bestbits.at⟩.
Linux ACL March 23, 2002 Linux ACL
