mq_setattr(2) [debian man page]

MQ_SETATTR(2)						      BSD System Calls Manual						     MQ_SETATTR(2)

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, 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 Elec-
     trical 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.

BSD
								 November 29, 2005							       BSD

MQ_SETATTR(3P)						     POSIX Programmer's Manual						    MQ_SETATTR(3P)

PROLOG

       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME

       mq_setattr - set message queue attributes (REALTIME)

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() function shall set attributes associated with the open message queue description referenced by the message queue  descrip-
       tor specified by mqdes.

       The  message  queue attributes corresponding to the following members defined in the mq_attr structure shall be set to the specified values
       upon successful completion of mq_setattr():

       mq_flags
	      The value of this member is the bitwise-logical OR of zero or more of O_NONBLOCK and any implementation-defined flags.

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

       If omqstat is non-NULL, the mq_setattr() function shall store, in the location referenced by omqstat, the previous message queue attributes
       and the current queue status. These values shall be the same as would be returned by a call to mq_getattr() at that point.

RETURN VALUE

       Upon  successful  completion,  the function shall return a value of zero and the attributes of the message queue shall have been changed as
       specified.

       Otherwise, the message queue attributes shall be unchanged, and the function shall return a value of -1	and  set  errno  to  indicate  the
       error.

ERRORS

       The mq_setattr() function shall fail if:

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

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       mq_open(),  mq_send(),  mq_timedsend(),	msgctl(),  msgget(),  msgrcv(),  msgsnd(),  the  Base  Definitions volume of IEEE Std 1003.1-2001,
       <mqueue.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 .

IEEE
/The Open Group						       2003							    MQ_SETATTR(3P)