message queue problem

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mq_send

mq_send(2)							System Calls Manual							mq_send(2)

NAME

       mq_send - send a message to a message queue

SYNOPSIS

DESCRIPTION

       The  system call adds a message pointed to by the argument msg_ptr to the message queue specified by mqdes.  The msg_len argument specifies
       the length of the message in bytes. The value of msg_len should be less than or equal to the mq_msgsize attribute of the message queue,	or
       will fail.

       If  the	specified  message queue is not full, will insert the message into the queue at the position indicated by the msg_prio argument. A
       message with priority, msg_prio, will be inserted behind any other messages with larger or equal priority.  The value of msg_prio should be
       less than

       If  the	specified  message queue is full and the flag is not set in the message queue blocking status associated with mqdes, will block in
       priority order, until it can send a message on the queue, or until is interrupted by a signal.  If the specified message queue is full  and
       the  flag  is  set  in  the  message queue blocking status associated with mqdes, the message will not be enqueued, and will return with an
       error.

       To use this function, link in the realtime library by specifying on the compiler or linker command line.

RETURN VALUE

       returns the following values:

	      Successful completion. The message is enqueued.

	      Failure.
		   is set to indicate the error and the message is not enqueued.

ERRORS

       If fails, is set to one of the following values:

	      [EAGAIN]	     The flag is set in the message queue blocking status associated with mqdes, and the message queue is full.

	      [EBADF]	     mqdes is not a valid message queue descriptor open for writing.

	      [EINTR]	     A signal interrupted the call to

	      [EINVAL]	     msg_ptr points to an invalid address, or the value of msg_prio is outside the valid range.

	      [EMSGSIZE]     The specified message length, msg_len, exceeds the message size attribute of the message queue.

	      [ENOSYS]	     is not supported by the implementation.

SEE ALSO

       mq_receive(2), mq_setattr(2), mq_getattr(2), sysconf(2).

STANDARDS CONFORMANCE

																	mq_send(2)

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