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mq_getattr(3)
NAME
  mq_getattr - Returns the status and attributes of a message queue
  (P1003.1b)

SYNOPSIS
  #include <mqueue.h>

  int mq_getattr (
  mqd_t mqdes,
  struct mq_attr *mqstat);

PARAMETERS
  mqdes	  Specifies the message queue descriptor whose attributes are
	  obtained.

  *mqstat A pointer a structure that is updated to contain the values that
	  were set when the message queue was created or modified by a call
	  to the mq_setattr function.

  When the mq_getattr function returns, the following three members of the
  mq_attr structure specified by mqstat will have the values that were set
  when the message queue was created, but with modifications made by
  subsequent calls to the mq_setattr function:

  ·  The mq_maxmsg member specifies the maximum number of messages that can
     be held in the queue specified by the mqdes argument.

  ·  The mq_msgsize member specifies the maximum size of any message in the
     queue.

  ·  The mq_flags member specifies whether the message operation is blocking
     or nonblocking (MQ_NONBLOCK).

  The mq_curmsgs member of the mq_attr structure indicates the number of
  messages currently on the queue.

DESCRIPTION
  Returns the status and attributes of a message queue. Use the mq_setattr
  function to set message queue attributes.

RETURN VALUES
  On successful completion, the function returns the value 0; otherwise, the
  function returns the value -1 and sets errno to indicate the error.

ERRORS
  The mq_getattr function fails under the following conditions:

  [EBADF]	 The fildes argument is an invalid file descriptor.

  [EINVAL]	 The mqstat argument is a null pointer.



RELATED INFORMATION
  Functions: mq_open(3), mq_receive(3), mq_send(3), mq_setattr(3)