mq_setattr(3)mq_setattr(3)NAMEmq_setattr - Sets the mq_options attributes associated with a message
queue (P1003.1b)
SYNOPSIS
#include <mqueue.h>
int mq_setattr ( mqd_t mqdes, const struct mq_attr *mqstat, struct
mq_attr *omqstat);
LIBRARY
Realtime Library (librt.so, librt.a)
PARAMETERS
Describes the message queue for which attributes are to be set. Speciā
fies a pointer to a mq_attr structure that specifies attributes to be
set for the specified message queue. Specifies a pointer to a mq_attr
structure that stores the previous message queue attributes and the
current queue status. These are the values that would be returned by a
call to the mq_getattr function at that point.
DESCRIPTION
The mq_setattr function sets the mq_options attributes associated with
the message queue descriptor for the calling process. Only the blocking
attribute of the queue for the calling process can be modified through
this call. Modifying the blocking attribute for a queue has no effect
on currently blocked processes. Other members of the mq_attr structure
are ignored by the mq_setattr function.
RETURN VALUES
On successful completion, the function returns the value 0 (zero) and
the message queue attributes will have been changed as specified.
Otherwise, the value -1 is returned, errno is set to indicate the
error, and the message queue attributes remain unchanged.
ERRORS
The mq_setattr function fails under the following conditions: The mqdes
argument is not a valid message queue descriptor. The mqstat argument
is a NULL pointer.
SEE ALSO
Functions: mq_open(3), mq_send(3)
Guide to Realtime Programming
mq_setattr(3)