This vnode call may be used to retrieve a specific named extended attribute
from a file or directory.
Its arguments are:
|
| vp
|
| |
The vnode of the file or directory.
|
| attrnamespace
|
| |
Integer constant indicating which extended attribute namespace the attribute
name is present in.
|
| name
|
| |
Pointer to a null-terminated character string containing the attribute name.
|
| uio
|
| |
The location of the data to be read.
|
| size
|
| |
If not
NULL,
on return it will contain the number of bytes required to read all of the
attribute data.
In most cases
uio
will be
NULL
when
size
is not, and vice versa.
|
| cred
|
| |
The user credentials to use in authorizing the request.
|
| td
|
| |
The thread requesting the extended attribute.
|
|
The
cred
pointer may be
NULL
to indicate that access control checks are not to be performed, if possible.
This
cred
setting might be used to allow the kernel to authorize extended attribute
retrieval that the active process might not be permitted to do.
Extended attribute semantics may vary by file system implementing the call.
More information on extended attributes may be found in
extattr(9).
