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mq_setattr(3)
NAME
  mq_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
  mqdes
      Describes the message queue for which attributes are to be set.

  *mqstat
      Specifies a pointer to a mq_attr structure that specifies attributes to
      be set for the specified message queue.

  *omqstat
      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:

  [EBADF]
      The mqdes argument is not a valid message queue descriptor.

  [EINVAL]
      The mqstat argument is a NULL pointer.

SEE ALSO
  Functions: mq_open(3), mq_send(3)

  Guide to Realtime Programming

Index for Section 3

Alphabetical listing for M

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