int
mq_setattr(
mqd_t mqdes
const struct mq_attr *restrict mqstat
struct mq_attr *restrict omqstat
)
)
function sets attributes associated with the open message queue
description referenced by the message queue descriptor specified by
mqdes.
The message queue attributes corresponding to the following members
defined in the
structure will be set to the specified values upon successful completion of
mq_setattr():
O_NONBLOCK
and any implementation-defined flags.
The values of the
mq_maxmsg,
mq_msgsize,
and
mq_curmsgs
members of the
structure will be ignored by
mq_setattr().
If
omqstat
is
non-NULL,
the
mq_setattr()
function will store, in the location referenced by
omqstat
the previous message queue attributes and the current queue status.
These values are the same as would be returned by a call to
mq_getattr(3)
at that point.
)
function returns zero and the attributes of the message queue will
have been changed as specified.
Otherwise, the message queue attributes are unchanged,
and the function returns a value of
-1 and sets the global variable
errno
to indicate the error.
)
function fails if:
EBADF]mqdes
argument is not a valid message queue descriptor.