.\" Access Control Lists manual pages
.\"
.\" (C) 2002 Andreas Gruenbacher, <a.gruenbacher@bestbits.at>
.\"
.\" This is free documentation; you can redistribute it and/or
.\" modify it under the terms of the GNU General Public License as
.\" published by the Free Software Foundation; either version 2 of
.\" the License, or (at your option) any later version.
.\"
.\" The GNU General Public License's references to "object code"
.\" and "executables" are to be interpreted as the output of any
.\" document formatting or typesetting system, including
.\" intermediate and printed output.
.\"
.\" This manual is distributed in the hope that it will be useful,
.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
.\" GNU General Public License for more details.
.\"
.\" You should have received a copy of the GNU General Public
.\" License along with this manual.  If not, see
.\" <http://www.gnu.org/licenses/>.
.\"
.Dd March 23, 2002
.Dt ACL_GET_FD 3
.Os "Linux ACL"
.Sh NAME
.Nm acl_get_fd
.Nd get an ACL by file descriptor
.Sh LIBRARY
Linux Access Control Lists library (libacl, \-lacl).
.Sh SYNOPSIS
.In sys/types.h
.In sys/acl.h
.Ft acl_t
.Fn acl_get_fd "int fd"
.Sh DESCRIPTION
The
.Fn acl_get_fd
function retrieves the access ACL associated with the file referred to by
.Va fd .
The ACL is placed into working storage and
.Fn acl_get_fd
returns a pointer to that storage.
.Pp
In order to read an ACL from an object, a process must have read access to
the object's attributes.
.Pp
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
.Xr acl_free 3
with the
.Va (void*)acl_t
returned by
.Fn acl_get_fd
as an argument.
.Sh RETURN VALUE
On success, this function shall return a pointer to the
working storage.  On error, a value of
.Li (acl_t)NULL
shall be returned, and
.Va errno
is set appropriately.
.Sh ERRORS
If any of the following conditions occur, the
.Fn acl_get_fd
function returns a value of
.Li (acl_t)NULL
and sets
.Va errno
to the corresponding value:
.Bl -tag -width Er
.It Bq Er EBADF
The
.Va fd
argument is not a valid file descriptor.
.It Bq Er ENOMEM
The ACL working storage requires more memory than is allowed by the hardware or system-imposed memory management constraints.
.It Bq Er ENOTSUP
The file system on which the file identified by
.Va fd
is located does not support ACLs, or ACLs are disabled.
.El
.Sh STANDARDS
IEEE Std 1003.1e draft 17 (\(lqPOSIX.1e\(rq, abandoned)
.Sh SEE ALSO
.Xr acl_free 3 ,
.Xr acl_get_entry 3 ,
.Xr acl_get_file 3 ,
.Xr acl_set_fd 3 ,
.Xr acl 5
.Sh AUTHOR
Derived from the FreeBSD manual pages written by
.An "Robert N M Watson" Aq rwatson@FreeBSD.org ,
and adapted for Linux by
.An "Andreas Gruenbacher" Aq a.gruenbacher@bestbits.at .