X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev.8;h=c0dc68b80360a2454a882ec319d2c255dde03a87;hp=f26beb4b9d1029e13c8f8238caa1ada5047d3dee;hb=a6f01502bd2a76d1f9d90abb7bbeebd8f6893ed9;hpb=3c54f73e8452261c80b4d17db55d199552442005

diff --git a/udev.8 b/udev.8
index f26beb4b9..c0dc68b80 100644
--- a/udev.8
+++ b/udev.8
@@ -3,11 +3,34 @@
 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
@@ -18,14 +41,14 @@ On device creation,
 .B udev
 reads the sysfs directory of the given device to collect device attributes
 like label, serial number or bus device number.
-These attributes are treated as a key
-to determine a unique name for device file creation.
+These attributes may used as keys to determine a
+unique name for device file creation.
 .B udev
 maintains a database for devices present on the system.
 .br
 On device removal,
 .B udev
-queries the internal database for the name of the device file to be deleted.
+queries its database for the name of the device file to be deleted.
 .SH "CONFIGURATION"
 All
 .B udev
@@ -35,7 +58,7 @@ lines, and lines beginning with a '#' will be ignored.
 
 .B udev
 expects its main configuration file at
-.I /etc/udev/udev.conf.
+.IR /etc/udev/udev.conf .
 The file consists of a set of variables and values that allow the user to
 override default udev values.  The current set of variables that can be
 overridden in this file is:
@@ -43,24 +66,46 @@ overridden in this file is:
 .B udev_root
 This is the where in the filesystem to place the device nodes.  The default
 value for this is
-.I /udev/
+.IR /udev/ .
 .TP
 .B udev_db
 The name and location of the udev database.  The default value for this is
-.I /udev/.udev.tdb
+.IR /udev/.udev.tdb .
 .TP
 .B udev_rules
 This is the location of the udev rules file.  The default value for this is
-.I /etc/udev/udev.rules
+.IR /etc/udev/udev.rules .
+If a directory is specified, the whole directory is
+scanned for files ending with
+.I .rules
+and all rule files are read in lexical order.
 .TP
 .B udev_permissions
-This is the location of the udev permission file.  The default value for this is
-.I /etc/udev/udev.permissions
+This is the location of the udev permission file. The default value for this is
+.IR /etc/udev/udev.permissions .
+If a directory is specified, the whole directory is scanned for files ending with
+.I .permissions
+and all permission files are read in lexical order.
+.TP
+.B udev_log
+If you want udev to log some information to the syslog for every node created or
+removed. The default value for this is
+.IR yes .
 .TP
 .B default_mode
 This is the default mode for all nodes that have no explicit match in the
 permissions file.  The default value for this is
-.I 0666
+.IR 0666 .
+.TP
+.B default_owner
+This is the default owner for all nodes that have no explicit match in the
+permissions file.  The default value for this is
+.IR root .
+.TP
+.B default_group
+This is the default group for all nodes that have no explicit match in the
+permissions file.  The default value for this is
+.IR root .
 .br
 .P
 .RI "A sample " udev.conf " might look like this:
@@ -72,15 +117,27 @@ udev_root="/udev/"
 # udev_db - The name and location of the udev database.
 udev_db="/udev/.udev.tdb"
 
-# udev_rules - The name and location of the udev rules file
-udev_rules="/etc/udev/udev.rules"
+# udev_rules - The location of the directory where to look for files
+               which names ending with .rules
+udev_rules="/etc/udev/"
 
 # udev_permissions - The name and location of the udev permission file
 udev_permissions="/etc/udev/udev.permissions"
 
-# default_mode - set the default mode for all nodes that have no 
+# udev_log - set to "yes" if you want logging, else "no"
+udev_log="yes"
+
+# default_mode - set the default mode for all nodes that have no
 #                explicit match in the permissions file
 default_mode="0666"
+
+# default_owner - set the default owner for all nodes that have no
+#                 explicit match in the permissions file
+default_owner="root"
+
+# default_group - set the default group for all nodes that have no
+#                 explicit match in the permissions file
+default_group="root"
 .fi
 .P
 The rules for udev to use when naming devices may specified at
@@ -91,55 +148,76 @@ value in the
 .I /etc/udev/udev.conf
 file.
 .P
-Every line in the rules file define 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 and the filename for the
-device. One ore more optional symlinks targeting the node may be specified.
+Every line in the rules file defines the mapping between device attributes
+and the device file name. One ore more keys are specified to match a rule
+with the current device. If all keys are matching, the rule will be applied
+and the name is used for the device node.
 .br
-If no matching configuration is found, the default kernel device name
-is used.
+If no matching rule is found, the default kernel device name is used.
 .P
-The line format is:
+Every rule consists of a list a comma separated fields:
 .sp
-.I method, key,[key,...] name [, symlink]
+.IR "key " ,[ "key " ,...] " name " [, " symlink" ]
 .sp
-where valid methods with corresponding keys are:
+where possible fields are:
 .TP
-.B CALLOUT
-calling external program, that returns a string to match
-.br
-.RB "keys: " BUS ", " PROGRAM ", " ID
+.B BUS
+Match the bus type of the device.
+(The sysfs device bus must be able to be determined by a "device" symlink.)
 .TP
-.B LABEL
-device label or serial number, like USB serial number, SCSI UUID or
-file system label
-.br
-.RB "keys: " BUS ", " SYSFS_
+.B KERNEL
+Match the kernel device name.
 .TP
-.B NUMBER
-device number on the bus, like PCI bus id
-.br
-.RB "keys: " BUS ", " ID
+.B ID
+Match the device number on the bus, like PCI bus id.
+.TP
+.B PLACE
+Match the topological position on bus, like physical port of USB device
+.TP
+.BI SYSFS{ filename }
+Match sysfs device attribute like label, vendor, USB serial number, SCSI UUID
+or file system label.  Up to 5 different sysfs files can be checked, with
+all of the values being required in order to match the rule.
 .TP
-.B TOPOLOGY
-device position on bus, like physical port of USB device
+.B PROGRAM
+Call external program. This key is valid if the program returns successful.
+The environment variables of
+.B udev
+are also available for the program.
 .br
-.RB "keys: " BUS ", " PLACE
+The string returned by the program may additionally matched with the
+.B RESULT
+key.
+.TP
+.B RESULT
+Match the returned string of the last
+.B PROGRAM
+call. This key may used in any following rule after a
+.B PROGRAM
+call.
 .TP
-.B REPLACE
-string replacement of the kernel device name
+.B NAME
+The name of the node to be created. If the name field is omitted or its
+value is empty, the device will be ignored and no node will be created.
 .br
-.RB "key: " KERNEL
-.P
-The methods are applied in the following order:
-.BR CALLOUT ", " LABEL ", " NUMBER ", " TOPOLOGY ", " REPLACE "."
+If given with the attribute
+.BR NAME{ all_partitions }
+it will  create all 15 partitions of a blockdevice.
+This may be useful for removable media devices.
+.TP
+.B SYMLINK
+The name of a symlink targeting the node. Multiple symlinks may be
+specified by separating the names by the space character.
 .P
 .RB "The " NAME " ," SYMLINK " and " PROGRAM
 fields support simple printf-like string substitution:
 .TP
 .B %n
 The "kernel number" of the device.
-for example, 'sda3' has a "kernel number" of '3'
+For example, 'sda3' has a "kernel number" of '3'.
+.TP
+.B %k
+The "kernel name" for the device.
 .TP
 .B %M
 The kernel major number for the device.
@@ -151,34 +229,50 @@ The kernel minor number for the device.
 The bus id for the device.
 .TP
 .B %c
-The CALLOUT program returned string.
-(This does not work within the PROGRAM field for the obvious reason.)
+The
+.B PROGRAM
+returned string.
+(This does not work within the
+.B PROGRAM
+field for the obvious reason.)
+.br
+A single part of the string, separated by the space character
+my be selected by specifying the part number as a attribute:
+.BI %c{ part }
 .TP
-.B %D
-Use the devfs style disk name for this device.
-For partitions, this will result in 'part%n'
-If this is not a partition, it will result in 'disc'.
+.BI %s{ filename }
+The content of a sysfs attribute.
+.TP
+.B %%
+The '%' character itself.
+.P
+The count of charcters to insert may be limited by specifying
+the format length value. For example, '%3s{file}' will only insert
+the first three characters of the sysfs attribute.
 .P
 .RI "A sample " udev.rules " might look like this:"
 .sp
 .nf
 # if /sbin/scsi_id returns "OEM 0815" device will be called disk1
-CALLOUT, BUS="scsi", PROGRAM="/sbin/scsi_id", ID="OEM 0815", NAME="disk1"
+BUS="scsi", PROGRAM="/sbin/scsi_id", RESULT="OEM 0815", NAME="disk1"
 
 # USB printer to be called lp_color
-LABEL, BUS="usb", SYSFS_serial="W09090207101241330", NAME="lp_color"
+BUS="usb", SYSFS{serial}="W09090207101241330", NAME="lp_color"
+
+# SCSI disk with a specific vendor and model number is to be called boot
+BUS="scsi", SYSFS{vendor}="IBM", SYSFS{model}="ST336", NAME="boot%n"
 
 # sound card with PCI bus id 00:0b.0 to be called dsp
-NUMBER, BUS="pci", ID="00:0b.0", NAME="dsp"
+BUS="pci", ID="00:0b.0", NAME="dsp"
 
 # USB mouse at third port of the second hub to be called mouse1
-TOPOLOGY, BUS="usb", PLACE="2.3", NAME="mouse1"
+BUS="usb", PLACE="2.3", NAME="mouse1"
 
 # ttyUSB1 should always be called pda with two additional symlinks
-REPLACE, KERNEL="ttyUSB1", NAME="pda", SYMLINK="palmtop handheld"
+KERNEL="ttyUSB1", NAME="pda", SYMLINK="palmtop handheld"
 
 # multiple USB webcams with symlinks to be called webcam0, webcam1, ...
-LABEL, BUS="usb", SYSFS_model="WebCam V3", NAME="video%n", SYMLINK="webcam%n"
+BUS="usb", SYSFS{model}="XV3", NAME="video%n", SYMLINK="webcam%n"
 .fi
 .P
 Permissions and ownership for the created device files may specified at
@@ -192,11 +286,6 @@ file.
 Every line lists a device name followed by owner, group and permission
 mode. All values are separated by colons. The name field may contain a
 pattern to apply the values to a whole class of devices.
-.br
-If
-.B udev
-was built using klibc or is used before the user database is accessible (e.g.
-.BR initrd "(4)), only numeric owner and group values may be used."
 .sp
 .RI "A sample " udev.permissions " might look like this:"
 .sp
@@ -208,6 +297,17 @@ video*:root:video:0660
 dsp1:::0666
 .fi
 .P
+The value
+.I $local
+can be substituted for a specific username.  In that case, udev will determine
+the current local user at the time of device node creation and substitute
+that username as the owner of the new device node.  This is useful, for
+example, to let hot-plugged devices, such as cameras, be owned by the user at
+the current console.  Note that if no user is currently logged in, or if udev
+otherwise fails to determine a current user, the
+.I default_owner
+value is used in lieu.
+.P
 A number of different fields in the above configuration files support a simple
 form of shell style pattern matching. It supports the following pattern characters:
 .TP
@@ -220,8 +320,8 @@ Matches any single character, but does not match zero characters.
 .B [ ]
 Matches any single character specified within the brackets. For example, the
 pattern string "tty[SR]" would match either "ttyS" or "ttyR".  Ranges are also
-supported within this match with the '-' character.  For example, to match on
-the range of all digits, the pattern [0-9] would be used. If the first character
+supported within this match with the '\-' character.  For example, to match on
+the range of all digits, the pattern [0\-9] would be used. If the first character
 following the '[' is a '!' then any character not enclosed is matched.
 .SH "FILES"
 .nf
@@ -231,10 +331,12 @@ following the '[' is a '!' then any character not enclosed is matched.
 .fi
 .LP
 .SH "SEE ALSO"
+.BR udevinfo (8),
+.BR udevd (8),
 .BR hotplug (8)
 .PP
 The
-.I http://linux-hotplug.sourceforge.net/
+.I http://linux\-hotplug.sourceforge.net/
 web site.
 .SH AUTHORS
 .B udev