.\"-
.\" Copyright (c) 2001 Chris D. Faulhaber
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.Dd March 13, 2001
.Dt ACL_GET_QUALIFIER 3
.Os
.Sh NAME
.Nm acl_get_qualifier
.Nd Retrieve the qualifier from an ACL entry
.Sh LIBRARY
.Lb libposix1e
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <sys/acl.h>
.Ft int
.Fn acl_get_qualifier "acl_entry_t entry_d"
.Sh DESCRIPTION
.Fn acl_get_qualifier
is a POSIX.1e call that retrieves the qualifier of the tag for
the ACL entry indicated by the argument
.Ar entry_d
into working storage and returns a pointer to that storage.
.Pp
If the value of the tag type in the ACL entry referred to by
.Ar entry_d
is ACL_USER, then the value returned by
.Fn acl_get_qualifier
will be a pointer to type uid_t.
.Pp
If the value of the tag type in
the ACL entry referred to by
.Ar entry_d
is ACL_GROUP, then the value returned by
.Fn acl_get_qualifier
will be a pointer to type gid_t.
.Pp
If the value of the tag type in the ACL enty referred to by
.Ar entry_d
is ACL_UNDEFINED_TAG, ACL_USER_OBJ, ACL_GROUP_OBJ, ACL_OTHER,
ACL_MASK, or an implementation-defined value for which a qualifier
is not supported, then
.Fn acl_get_qualifier
will return a valid of (void *)NULL and the function will fail.
.Pp
This function may cause memory to be allocated.  The caller should
free any releasable memory, when the new qualifier is no longer
required, by calling
.Fn acl_free
with void* as the argument.
.Sh RETURN VALUES
Upon successful completion, the function will return a value of
.Va 0 .
Otherwise, a value of
.Va -1
will be returned, and
.Va errno
will be set to indicate the error.
.Sh ERRORS
If any of the following conditions occur, the
.Fn acl_get_qualifier
function will return a value of
.Va (void *)NULL
and set
.Va errno
to the corresponding value:
.Bl -tag -width Er
.It Bq Er EINVAL
Argument
.Ar entry_d
does not point to a valid descriptor for an ACL entry.  The
value of the tag type in the ACL entry referenced by argument
.Ar entry_d
is not ACL_USER or ACL_GROUP.
.It Bq Er ENOMEM
The value to be returned requires more memory than is allowed
by the hardware or system-imposed memory management constraints.
.El
.Sh SEE ALSO
.Xr acl 3 ,
.Xr acl_create_entry 3 ,
.Xr acl_free 3 ,
.Xr acl_get_entry 3 ,
.Xr acl_get_tag_type 3 ,
.Xr acl_set_qualifier 3 ,
.Xr acl_set_tag_type 3 ,
.Xr posix1e 3
.Sh STANDARDS
POSIX.1e is described in IEEE POSIX.1e draft 17.
.Sh HISTORY
POSIX.1e support was introduced in
.Fx 4.0 .
The
.Fn acl_get_qualifier
function was added in
.Fx 5.0 .
.Sh AUTHORS
The
.Fn acl_get_qualifier
function was written by
.An Chris D. Faulhaber Aq jedgar@fxp.org .