mq_setattr(3RT) Realtime Library Functions mq_setattr(3RT)
NAME
mq_setattr - set/get message queue attributes
SYNOPSIS
cc [ flag... ] file... -lrt [ library... ]
#include <mqueue.h>
int mq_setattr(mqd_t mqdes, const struct mq_attr *mqstat, struct mq_attr *omqstat);
DESCRIPTION
The mq_setattr() function is used to set 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 are set to the specified values upon
successful completion of mq_setattr():
mq_flags The value of this member is either 0 or O_NONBLOCK.
The values of mq_maxmsg, mq_msgsize, and mq_curmsgs are ignored by mq_setattr().
If omqstat is non-NULL, mq_setattr() stores, in the location referenced by omqstat, the previous message queue attributes and the current
queue status. These values are the same as would be returned by a call to mq_getattr() at that point.
RETURN VALUES
Upon successful completion, mq_setattr() returns 0 and the attributes of the message queue will have been changed as specified. Otherwise,
the message queue attributes are unchanged, and the function returns -1 and sets errno to indicate the error.
ERRORS
The mq_setattr() function will fail if:
EBADF The mqdes argument is not a valid message queue descriptor.
ENOSYS The mq_setattr() function is not supported by the system.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
SEE ALSO
msgctl(2), msgget(2), msgrcv(2), msgsnd(2), mq_getattr(3RT), mq_open(3RT), mq_receive(3RT), mq_send(3RT), mqueue.h(3HEAD), attributes(5),
standards(5)
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.
SunOS 5.10 14 May 2002 mq_setattr(3RT)