udev \- Linux configurable dynamic device naming support
.SH SYNOPSIS
.BI udev " hotplug-subsystem"
+.P
+The environment must provide the following variables:
+.TP
+.B ACTION
+.IR add " or " remove
+signifies the connection or disconnection of a device.
+.TP
+.B DEVPATH
+The sysfs devpath of the device without the mountpoint but a leading slash.
+.P
+Additional optional environment variables are:
+.TP
+.B UDEV_CONFIG_FILE
+Overrides the default location of the
+.B udev
+config file.
+.TP
+.B UDEV_NO_SLEEP
+The default behavior of
+.B udev
+is to wait until all the sysfs files of the device chain are populated. If set
+.B udev
+will will continue, regardless of the state of the device representation.
.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.
+It provides a dynamic device directory that contains only the files for
+devices that are actually present.
.P
As part of the
.B hotplug
.TP
.B PROGRAM
Call external program. This key is valid if the program returns successful.
+A few command line options may specified, but shell characters like pipe,
+diversion or similiar options are not available. The environment variables of
+.B udev
+are also available for the program.
+.br
The string returned by the program may additionally matched with the
.B RESULT
key.
.LP
.SH "SEE ALSO"
.BR udevinfo (8),
+.BR udevd (8),
.BR hotplug (8)
.PP
The
udevd \- udev event serializer daemon
.br
udevsend \- sends the event to udevd
+.SH SYNOPSIS
+.BI udevsend " hotplug-subsystem"
+.sp
+The environment must provide the following variables:
+.TP
+.B ACTION
+.IR add " or " remove
+signifies the connection or disconnection of a device.
+.TP
+.B DEVPATH
+The sysfs devpath of the device without the mountpoint but a leading slash.
+.TP
+.B SEQNUM
+The sequence number of the event provided by the kernel.
+If unset, the event bypasses the queue and will be executed immediately.
.SH "DESCRIPTION"
.B udevd
allows the serialization of
.B udevsend
will start it.
.SH "SEE ALSO"
-.BR udev (8), " hotplug" (8)
+.BR udev (8),
+.BR udevinfo (8),
+.BR hotplug (8)
.SH AUTHORS
.B udevd
was developed primarily by Kay Sievers <kay.sievers@vrfy.org>, with much help