Originální popis anglicky:
mq_getattr - get message queue attributes (
REALTIME)
Návod, kniha: POSIX Programmer's Manual
#include <mqueue.h>
int mq_getattr(mqd_t
mqdes, struct mq_attr
*mqstat);
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.
Upon successful completion, the
mq_getattr() function shall return zero.
Otherwise, the function shall return -1 and set
errno to indicate the
error.
The
mq_getattr() function shall fail if:
- EBADF
- The mqdes argument is not a valid message queue
descriptor.
The following sections are informative.
None.
None.
None.
None.
mq_open() ,
mq_send() ,
mq_setattr() ,
mq_timedsend() ,
msgctl() ,
msgget() ,
msgrcv() ,
msgsnd() , the Base Definitions volume of
IEEE Std 1003.1-2001,
<mqueue.h>
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
.