mq_close.2 (2010 09)

mq_close(2) mq_close(2)

NAME

mq_close - close a message queue descriptor

SYNOPSIS

#include <sys/mqueue.h>

int mq_close(mqd_t mqdes);

DESCRIPTION

The mq_close() system call removes the association between the message queue descriptor, mqdes,

and a message queue. Use of this message queue descriptor by the process, after a successful return from

this

mq_close(), and until this descriptor is returned by a subsequent

mq_open(), will result in the

failure of message queue system calls, with

errno

set to [EBADF].

If the process has successfully attached a notiﬁcation request to the message queue via this mqdes, this

attachment shall be removed, and the message queue is available for another process to attach for

notiﬁcation.

If the message queue has been unlinked and mqdes is the only existing open descriptor for the queue, the

queue is destroyed.

To use this function, link in the realtime library by specifying

-lrt on the compiler or linker command

line.

RETURN VALUE

mq_close() returns the following values:

0 Successful completion.

-1 Failure. errno is set to indicate the error.

ERRORS

mq_close() fails, errno is set to one of the following values:

[EBADF] mqdes is not a valid message queue descriptor.

[ENOSYS]

mq_close() is not supported by the implementation.