[PATCH] fix NAME="foo-%c{N}" gets a truncated name

[elogind.git] / udev.8

diff --git a/udev.8 b/udev.8
index e46caaf3226d62fde14fb96417230e407b58559d..c0dc68b80360a2454a882ec319d2c255dde03a87 100644 (file)
--- a/udev.8
+++ b/udev.8
@@ -3,11 +3,34 @@
 udev \- Linux configurable dynamic device naming support
 .SH SYNOPSIS
 .BI udev " hotplug-subsystem"
 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.
 .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
 .P
 As part of the
 .B hotplug


@@ -18,133 +41,305 @@ 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.
 .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
 .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"
 .SH "CONFIGURATION"

+All
+.B udev
+configuration files consist of a set of lines of text.  All empty
+lines, and lines beginning with a '#' will be ignored.
+.P
+

 .B udev
 .B udev

-expects its configuration at
-.I /etc/udev/udev.config.
-The file consists of a set of lines. All empty lines and
-lines beginning with a '#' will be ignored.
+expects its main configuration file at
+.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:
+.TP
+.B udev_root
+This is the where in the filesystem to place the device nodes.  The default
+value for this is
+.IR /udev/ .
+.TP
+.B udev_db
+The name and location of the udev database.  The default value for this is
+.IR /udev/.udev.tdb .
+.TP
+.B udev_rules
+This is the location of the udev rules file.  The default value for this is
+.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
+.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
+.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:
+.sp
+.nf
+# udev_root - where in the filesystem to place the device nodes
+udev_root="/udev/"
+
+# udev_db - The name and location of the udev database.
+udev_db="/udev/.udev.tdb"
+
+# 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"
+
+# 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
+.I /etc/udev/udev.rules
+or specified by the
+.I udev_rules
+value in the
+.I /etc/udev/udev.conf
+file.
+.P
+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
 .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 and the filename for the device. 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
 .P

-The line format is:
-.RS
+Every rule consists of a list a comma separated fields:

 .sp
 .sp

-.I method, key,[key,...] name
+.IR "key " ,[ "key " ,...] " name " [, " symlink" ]

 .sp
 .sp

-.RE
-where valid methods with corresponding keys are:
+where possible fields are:

 .TP
 .TP

-.B LABEL
-device label or serial number, like USB serial number, SCSI UUID or
-file system label
-.br
-keys: \fBBUS\fP, \fIsysfs_attribute\fP
+.B BUS
+Match the bus type of the device.
+(The sysfs device bus must be able to be determined by a "device" symlink.)

 .TP
 .TP

-.B NUMBER
-device number on the bus, like PCI bus id
-.br
-keys: \fBBUS\fP, \fBID\fP
+.B KERNEL
+Match the kernel device name.

 .TP
 .TP

-.B TOPOLOGY
-device position on bus, like physical port of USB device
-.br
-keys: \fBBUS\fP, \fBPLACE\fP
+.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
 .TP

-.B REPLACE
-string replacement of the kernel device name
+.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 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
 .br

-key: \fBKERNEL_NAME\fP
+The string returned by the program may additionally matched with the
+.B RESULT
+key.

 .TP
 .TP

-.B CALLOUT
-calling external program, that returns a string to match
+.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 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
 .br

-keys: \fBBUS\fP, \fBPROGRAM\fP, \fBID\fP
+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
 .P

-The name field supports simple printf-like string subtitution:
-.RS
+.RB "The " NAME " ," SYMLINK " and " PROGRAM
+fields support simple printf-like string substitution:

 .TP
 .B %n
 .TP
 .B %n

-the "kernel number" of the device
-for example, 'sda3' has a "kernel number" of '3'
+The "kernel number" of the device.
+For example, 'sda3' has a "kernel number" of '3'.
+.TP
+.B %k
+The "kernel name" for the device.

 .TP
 .B %M
 .TP
 .B %M

-the kernel major number for the device
+The kernel major number for the device.

 .TP
 .B %m
 .TP
 .B %m

-the kernel minor number for the device
+The kernel minor number for the device.

 .TP
 .B %b
 .TP
 .B %b

-the bus id for the device
-.RE
+The bus id for the device.
+.TP
+.B %c
+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
+.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
 .P

-A sample \fIudev.conf\fP might look like this:
+.RI "A sample " udev.rules " might look like this:"

 .sp
 .nf
 .sp
 .nf

+# if /sbin/scsi_id returns "OEM 0815" device will be called disk1
+BUS="scsi", PROGRAM="/sbin/scsi_id", RESULT="OEM 0815", NAME="disk1"
+

 # USB printer to be called lp_color
 # USB printer to be called lp_color

-LABEL, BUS="usb", 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
 
 # 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
 
 # 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
-REPLACE, KERNEL="ttyUSB1", NAME="pda"
+# ttyUSB1 should always be called pda with two additional symlinks
+KERNEL="ttyUSB1", NAME="pda", SYMLINK="palmtop handheld"

 
 

-# if /sbin/scsi_id returns "OEM 0815" device will be called disk1
-CALLOUT, PROGRAM="/sbin/scsi_id" BUS="scsi", ID="OEM 0815" NAME="disk1"
-
-# USB webcams to be called webcam0, webcam1, ...
-LABEL, BUS="usb", model="WebCam Version 3", NAME="webcam%n"
+# multiple USB webcams with symlinks to be called webcam0, webcam1, ...
+BUS="usb", SYSFS{model}="XV3", NAME="video%n", SYMLINK="webcam%n"

 .fi
 .P
 Permissions and ownership for the created device files may specified at
 .fi
 .P
 Permissions and ownership for the created device files may specified at

-.I /etc/udev/udev.permissions.
-The file consists of a set of lines. All empty lines and
-lines beginning with a '#' will be ignored.
+.I /etc/udev/udev.permissions
+or specified by the
+.I udev_permission
+value in the
+.I /etc/udev/udev.conf
+file.

 .br
 .br

-Every line lists a device name followed by numeric owner, group and permission
-mode. All values are separated by colons. The name field may end with a
-wildcard to apply the values to a whole class of devices.
+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.

 .sp
 .sp

-A sample \fIudev.permissions\fP might look like this:
+.RI "A sample " udev.permissions " might look like this:"

 .sp
 .nf
 #name:user:group:mode
 .sp
 .nf
 #name:user:group:mode

+input/*:root:root:644

 ttyUSB1:0:8:0660
 ttyUSB1:0:8:0660

-video*:500:500:0660
+video*:root:video:0660

 dsp1:::0666
 .fi
 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
+.B *
+Matches zero, one, or more characters.
+.TP
+.B ?
+Matches any single character, but does not match zero characters.
+.TP
+.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
+following the '[' is a '!' then any character not enclosed is matched.

 .SH "FILES"
 .nf
 .SH "FILES"
 .nf

-.ft B
-.ft

 /sbin/udev                           udev program
 /sbin/udev                           udev program

-/etc/udev/*                          udev config and database files
+/etc/udev/*                          udev config files

 /etc/hotplug.d/default/udev.hotplug  hotplug symlink to udev program
 .fi
 .LP
 .SH "SEE ALSO"
 /etc/hotplug.d/default/udev.hotplug  hotplug symlink to udev program
 .fi
 .LP
 .SH "SEE ALSO"

+.BR udevinfo (8),
+.BR udevd (8),

 .BR hotplug (8)
 .PP
 The
 .BR hotplug (8)
 .PP
 The

-.I http://linux-hotplug.sourceforge.net/
+.I http://linux\-hotplug.sourceforge.net/

 web site.
 .SH AUTHORS
 .B udev
 was developed by Greg Kroah-Hartman <greg@kroah.com> with much help from
 web site.
 .SH AUTHORS
 .B udev
 was developed by Greg Kroah-Hartman <greg@kroah.com> with much help from

-Dan Stekloff <dsteklof@us.ibm.com> and many others.
+Dan Stekloff <dsteklof@us.ibm.com>, Kay Sievers <kay.sievers@vrfy.org>, and
+many others.