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devfs(5) [freebsd man page]

DEVFS(5)						      BSD File Formats Manual							  DEVFS(5)

devfs -- device file system SYNOPSIS
devfs /dev devfs rw 0 0 DESCRIPTION
The device file system, or devfs, provides access to kernel's device namespace in the global file system namespace. The conventional mount point is /dev. The file system includes several directories, links, symbolic links and devices, some of which can also be written. In a chroot'ed environ- ment, devfs can be used to create a new /dev mount point. The mknod(8) tool can be used to recover deleted device entries under devfs. The fdescfs(5) filesystem is an alternate means for populating /dev/fd. The character devices that both devfs and fdescfs(5) present in /dev/fd correspond to the open file descriptors of the process accessing the directory. devfs only creates files for the standard file descriptors 0, 1 and 2. fdescfs(5) creates files for all open descriptors. The options are as follows: -o options Use the specified mount options, as described in mount(8). The following devfs file system-specific options are available: ruleset=ruleset Set ruleset number ruleset as the current ruleset for the mount-point and apply all its rules. If the ruleset number ruleset does not exist, an empty ruleset with the number ruleset is created. See devfs(8) for more information on working with devfs rulesets. FILES
/dev The normal devfs mount point. EXAMPLES
To mount a devfs volume located on /mychroot/dev: mount -t devfs devfs /mychroot/dev SEE ALSO
fdescfs(5), devfs(8), mount(8) HISTORY
The devfs file system first appeared in FreeBSD 2.0. It became the preferred method for accessing devices in FreeBSD 5.0 and the only method in FreeBSD 6.0. The devfs manual page first appeared in FreeBSD 2.2. AUTHORS
The devfs manual page was written by Mike Pritchard <>. BSD
February 9, 2012 BSD

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DEVFS.RULES(5)						      BSD File Formats Manual						    DEVFS.RULES(5)

devfs.rules -- devfs configuration information DESCRIPTION
The devfs.rules file provides an easy way to create and apply devfs(8) rules, even for devices that are not available at boot. For devices available at boot, see devfs.conf(5). The format of this file is simple. Empty lines and lines beginning with a hash sign ('#') are ignored. A line between brackets denotes the start of a ruleset. In the brackets should be the name of the ruleset and its number, separated by an equal sign. Other lines are rule specifications as documented in devfs(8), in the section Rule Specification. These lines are prepended with ``rule'' and are passed to devfs(8) by the startup scripts of the system. It is important to put path elements that contain glob(3) special charac- ters between quotes. Rulesets should have a unique name and number. All rules that follow a ruleset declaration belong to that ruleset, until a new ruleset is started. One custom ruleset has to be enabled in /etc/rc.conf, otherwise it will not be applied to the /dev file system by the default system startup process. For example, to enable a ``localrules'' ruleset for the /dev file system, you would have to use something like this in your rc.conf file: devfs_system_ruleset="localrules" FILES
/etc/defaults/devfs.rules Default devfs.rules configuration file. /etc/devfs.rules Local devfs.rules configuration file. Rulesets in here override those in /etc/defaults/devfs.rules with the same ruleset number, otherwise the two files are effectively merged. EXAMPLES
To make all the partitions of da(4) devices readable and writable by their owner and the ``usb'' group, the following rule may be used: [localrules=10] add path 'da*s*' mode 0660 group usb The first line declares and starts a new ruleset, with the name localrules and the number 10. To give usbconfig(8) and libusb(3) enabled applications permission to all usb devices for their owner and the ``usb'' group, a similar rule may be used: add path 'usb/*' mode 0660 group usb SEE ALSO
glob(3), devfs(5), devfs.conf(5), devfs(8) AUTHORS
This manual page was written by Roland Smith <>. BSD
February 21, 2010 BSD
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