.SH NAME
udev \- Linux configurable dynamic device naming support
.SH SYNOPSIS
-.B udev
+.BI udev " hotplug-subsystem"
.SH "DESCRIPTION"
.B udev
creates or removes device node files usually located in the /dev directory.
+Its goal is to provide a dynamic device directory that contains only the files
+for devices that are actually present.
+.P
As part of the
.B hotplug
subsystem,
.B udev
-is exectuted if a kernel device is added or removed from the system.
-.P
+is executed if a kernel device is added or removed from the system.
On device creation,
.B udev
-reads the sysfs directory of the given device, to collect device attributes
+reads the sysfs directory of the given device to collect device attributes
like label, serial number or bus device number.
These attributes are passed as a key to the namedev subsystem
to receive a unique name for device file creation.
namedev maintains a database for devices present on the system.
-.P
+.br
On device removal,
.B udev
-queries the namedev database for the name of the device file to delete.
-.P
+queries the namedev database for the name of the device file to be deleted.
+.SH "CONFIGURATION"
namedev expects its configuration at
.I /etc/udev/namedev.config.
The file consists of a set of lines. All empty lines and
.br
Every line defines the mapping between device attributes and the device file
name. It starts with a keyword defining the method used to match, followed by
-one ore more keys to compare, optional ownwership and permission settings and
-the filename for the device. If no matching configuration is found,
-the default kernel device name is used.
+one ore more keys to compare and the filename for the device. If no matching
+configuration is found, the default kernel device name is used.
.P
-.I method, key,[key,...] [owner,] [group,] [mode,] name
+The line format is:
+.RS
+.sp
+.I method, key,[key,...] name
+.sp
+.RE
+where valid methods with corresponding keys are:
.TP
.B LABEL
device label or serial number, like USB serial number, SCSI UUID or
calling external program, that returns a string to match
.br
keys: \fBBUS\fP, \fBPROGRAM\fP, \fBID\fP
-.SH "EXAMPLE"
+.P
+A sample \fInamedev.conf\fP might look like this:
+.sp
.nf
# USB printer to be called lp_color
LABEL, BUS="usb", serial="W09090207101241330", NAME="lp_color"
# if /sbin/dev_id returns "V0815" device will be called dev0815
CALLOUT, PROGRAM="/sbin/dev_id", BUS="pci", ID="V0815", NAME="dev0815"
.fi
+.P
+Permissions and ownership for the created device files may specified at
+.I /etc/udev/namedev.permissions.
+The file consists of a set of lines. All empty lines and
+lines beginning with a '#' will be ignored.
+.br
+Every line lists a device name followed by owner, group and permission mode. All values are separated by colons.
+.sp
+A sample \fInamedev.permissions\fP might look like this:
+.sp
+.nf
+#name:user:group:mode
+ttyUSB1:root:uucp:0666
+dsp1:::0666
+.fi
+
.SH "FILES"
.nf
.ft B
.fi
.LP
.SH "SEE ALSO"
-.B hotplug (8)
+.BR hotplug (8)
.PP
The
.I http://linux-hotplug.sourceforge.net/