MQ_GETATTR(3C) Standard C Library Functions MQ_GETATTR(3C)

NAME

mq_getattr - get message queue attributes

SYNOPSIS

#include <mqueue.h>

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

DESCRIPTION

The mqdes argument specifies a message queue descriptor. The
mq_getattr() function is used to get status information and
attributes of the message queue and the open message queue
description associated with the message queue descriptor. The results
are returned in the mq_attr structure referenced by the mqstat
argument.


Upon return, the following members will 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(3C) calls:

mq_flags
message queue flags


The following attributes of the message queue are returned as set at
message queue creation:

mq_maxmsg
maximum number of messages


mq_msgsize
maximum message size


mq_curmsgs
number of messages currently on the queue.

RETURN VALUES

Upon successful completion, the mq_getattr() function returns 0.
Otherwise, the function returns -1 and sets errno to indicate the
error.

ERRORS

The mq_getattr() function will fail if:

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


ENOSYS
The mq_getattr() function is not supported by the system.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|Interface Stability | Committed |
+--------------------+-------------------+
|MT-Level | MT-Safe |
+--------------------+-------------------+
|Standard | See standards(7). |
+--------------------+-------------------+

SEE ALSO

msgctl(2), msgget(2), msgrcv(2), msgsnd(2), mq_open(3C), mq_send(3C),
mq_setattr(3C), mqueue.h(3HEAD), attributes(7), standards(7)

NOTES

Solaris 2.6 was the first release to support the Asynchronous Input
and Output option. Prior to this release, this function always
returned -1 and set errno to ENOSYS.

February 5, 2008 MQ_GETATTR(3C)