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MQUEUEFS(5) BSD File Formats Manual MQUEUEFS(5)
NAME
mqueuefs -- POSIX message queue file system
SYNOPSIS
To link into kernel:
options P1003_1B_MQUEUE
To load as a kernel loadable module:
kldload mqueuefs
DESCRIPTION
The mqueuefs module will permit the FreeBSD kernel to support POSIX message queue. The module contains system calls to manipulate POSIX mes-
sage queues. It also contains a file system to implement a view for all message queues of the system. This helps users to keep track of
their message queues and make it more easily usable without having to invent additional tools.
The most common usage is as follows:
mount -t mqueuefs null /mnt/mqueue
where /mnt/mqueue is a mount point.
It is possible to define an entry in /etc/fstab that looks similar to:
null /mnt/mqueue mqueuefs rw 0 0
This will mount mqueuefs at the /mnt/mqueue mount point during system boot. Using /mnt/mqueue as a permanent mount point is not advised as
its intention has always been to be a temporary mount point. See hier(7) for more information on FreeBSD directory layout.
Some common tools can be used on the file system, e.g.: cat(1), chmod(1), chown(8), ls(1), rm(1), etc. To use only the message queue system
calls, it is not necessary for user to mount the file system, just load the module or compile it into the kernel. Manually creating a file,
for example, ``touch /mnt/mqueue/myqueue'', will create a message queue named myqueue in the kernel, default message queue attributes will be
applied to the queue. It is not advised to use this method to create a queue; it is better to use the mq_open(2) system call to create a
queue as it allows the user to specify different attributes.
To see the queue's attributes, just read the file:
cat /mnt/mqueue/myqueue
SEE ALSO
mq_open(2), nmount(2), unmount(2), mount(8), umount(8)
AUTHORS
This manual page was written by David Xu <davidxu@FreeBSD.org>.
BSD
November 30, 2005 BSD