NAME¶
acl_extended_fd
—
test for information in the ACL by file
descriptor
LIBRARY¶
Linux Access Control Lists library (libacl, -lacl).
SYNOPSIS¶
#include
<sys/types.h>
#include
<acl/libacl.h>
int
acl_extended_fd
(
int
fd);
DESCRIPTION¶
The
acl_extended_fd
() function returns
1
if the file identified by the argument
fd is associated with an extended access ACL.
The function returns
0
if the file does not have an
extended access 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_fd
() function for a
file object is
0
, then the ACL defines 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.
RETURN VALUE¶
If successful, the
acl_extended_fd
() function
returns
1
if the file object identified by
fd has an extended access ACL, and
0
if the file object identified by
fd does not have an extended access 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_fd
() function returns
-1
and sets
errno to
the corresponding value:
- [
EBADF
]
- The fd argument is not a valid file
descriptor.
- [
ENOTSUP
]
- The file system on which the file identified by
fd 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¶
access(2),
acl_get_fd(3),
acl(5)
AUTHOR¶
Written by
Andreas Gruenbacher
⟨a.gruenbacher@bestbits.at⟩.