table of contents
ACL_EXTENDED_FILE(3) | 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 themselves, 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
() 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 directory.
- [
ENOTSUP
] - The file system on which the file identified by path_p is located does not support ACLs, or ACLs are disabled.
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¶
AUTHOR¶
Written by
Andreas Gruenbacher
⟨andreas.gruenbacher@gmail.com⟩.
March 23, 2002 | Linux ACL |