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.\" (C) 2002 Andreas Gruenbacher, <a.gruenbacher@bestbits.at>

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.Dd March 23, 2002

.Dt ACL_GET_QUALIFIER 3

.Os "Linux ACL"

.Sh NAME

.Nm acl_get_qualifier

.Nd retrieve the qualifier from an ACL entry

.Sh LIBRARY

Linux Access Control Lists library (libacl, \-lacl).

.Sh SYNOPSIS

.In sys/types.h

.In sys/acl.h

.Ft void *

.Fn acl_get_qualifier "acl_entry_t entry_d"

.Sh DESCRIPTION

The

.Fn acl_get_qualifier

function retrieves the qualifier from the ACL entry indicated by the argument

.Va 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

.Va entry_d

is ACL_USER, then the value returned by

.Fn acl_get_qualifier

is a pointer to type

.Va uid_t .

If the value of the tag type in the ACL entry referred to by

.Va entry_d

is ACL_GROUP, then the value returned by

.Fn acl_get_qualifier

is a pointer to type

.Va gid_t .

If the tag type in the ACL entry referred to by

.Va entry_d

is a tag type for which a qualifier is not supported,

.Fn acl_get_qualifier

returns a value of

.Li (void *)NULL

and the function fails. Subsequent operations using the returned pointer

operate on an independent copy of the qualifier in working storage, and will not change the qualifier of the ACL entry.

.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 the

.Va void *

value returned by

.Fn acl_get_qualifier

as an argument.

.Pp

The argument

.Va entry_d

and any other ACL entry descriptors that refer to entries within the ACL

containing the entry referred to by

.Va entry_d

continue to refer to those entries. The order of all existing

entries in the ACL containing the entry referred to by

.Va entry_d

remains unchanged.

.Sh RETURN VALUE

On success, the function returns a pointer to the tag qualifier that was retrieved into ACL working storage. On error, a value of

.Li (void *)NULL

is returned and

.Va errno

is set appropriately.

.Sh ERRORS

If any of the following conditions occur, the

.Fn acl_get_qualifier

function returns

.Li (void *)NULL

and sets

.Va errno

to the corresponding value:

.Bl -tag -width Er

.It Bq Er EINVAL

The argument

.Va entry_d

is not a valid descriptor for an ACL entry.

.Pp

The value of the tag type in the ACL entry referenced by the argument

.Va entry_d

is neither ACL_USER nor 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 STANDARDS

IEEE Std 1003.1e draft 17 (\(lqPOSIX.1e\(rq, abandoned)

.Sh SEE ALSO

.Xr acl_create_entry 3 ,

.Xr acl_free 3 ,

.Xr acl_get_entry 3 ,

.Xr acl_get_permset 3 ,

.Xr acl_get_tag_type 3 ,

.Xr acl_set_permset 3 ,

.Xr acl_set_qualifier 3 ,

.Xr acl_set_tag_type 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 .