MQUEUEFS(5)               FreeBSD 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
     message 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>.

FreeBSD 13.1-RELEASE-p6        November 30, 2005       FreeBSD 13.1-RELEASE-p6