NAME

       mq_setattr — set message queue attributes (REALTIME)

LIBRARY

       POSIX Real-time Library (librt, -lrt)

SYNOPSIS

       #include <mqueue.h>

       int
       mq_setattr(mqd_t mqdes, const struct mq_attr *restrict mqstat, struct mq_attr *restrict omqstat);

DESCRIPTION

       The  mq_setattr()  system  call  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 mq_attr structure will be set to the specified
       values upon successful completion of mq_setattr():

       mq_flags  The value of this member is zero or O_NONBLOCK.

       The values of the mq_maxmsg, mq_msgsize, and mq_curmsgs members of the mq_attr structure are  ignored  by
       mq_setattr().

RETURN VALUES

       Upon  successful completion, the function returns a value of 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.

ERRORS

       The mq_setattr() system call will fail if:

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

SEE ALSO

       mq_open(2), mq_send(2), mq_timedsend(2)

STANDARDS

       The mq_setattr() system call conforms to IEEE Std 1003.1-2004 (“POSIX.1”).

HISTORY

       Support for POSIX message queues first appeared in FreeBSD 7.0.

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2004 Edition,
       Standard  for  Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers,
       Inc and The Open Group.  In the event of any discrepancy between this version and the original  IEEE  and
       The  Open  Group  Standard,  the  original IEEE and The Open Group Standard is the referee document.  The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html.

Debian                                            May 17, 2011                                     MQ_SETATTR(2)