NAME

       mq_getattr - get message queue attributes (REALTIME)

SYNOPSIS

       #include <mqueue.h>

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

DESCRIPTION

       The  mq_getattr()  function  shall obtain status information and attributes of the message
       queue and the open message queue description associated with the message queue descriptor.

       The mqdes argument specifies a message queue descriptor.

       The results shall be returned in the mq_attr structure referenced by the mqstat argument.

       Upon return, the following members shall have the values associated with the open  message
       queue  description  as set when the message queue was opened and as modified by subsequent
       mq_setattr() calls: mq_flags.

       The following attributes of the message queue shall be returned as set  at  message  queue
       creation: mq_maxmsg, mq_msgsize.

       Upon  return,  the following members within the mq_attr structure referenced by the mqstat
       argument shall be set to the current state of the message queue:

       mq_curmsgs
              The number of messages currently on the queue.

RETURN VALUE

       Upon successful completion, the mq_getattr() function shall return  zero.  Otherwise,  the
       function shall return -1 and set errno to indicate the error.

ERRORS

       The mq_getattr() 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_setattr() , 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 Technology -- 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 .