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Diffstat (limited to 'udev-lfs/udev.7')
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diff --git a/udev-lfs/udev.7 b/udev-lfs/udev.7 deleted file mode 100644 index 472651bcc..000000000 --- a/udev-lfs/udev.7 +++ /dev/null @@ -1,476 +0,0 @@ -'\" t -.TH "UDEV" "7" "" "systemd 202" "udev" -.\" ----------------------------------------------------------------- -.\" * Define some portability stuff -.\" ----------------------------------------------------------------- -.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -.\" http://bugs.debian.org/507673 -.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html -.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -.ie \n(.g .ds Aq \(aq -.el .ds Aq ' -.\" ----------------------------------------------------------------- -.\" * set default formatting -.\" ----------------------------------------------------------------- -.\" disable hyphenation -.nh -.\" disable justification (adjust text to left margin only) -.ad l -.\" ----------------------------------------------------------------- -.\" * MAIN CONTENT STARTS HERE * -.\" ----------------------------------------------------------------- -.SH "NAME" -udev \- Linux dynamic device management -.SH "DESCRIPTION" -.PP -udev supplies the system software with device events, manages permissions of device nodes and may create additional symlinks in the -/dev -directory, or renames network interfaces\&. The kernel usually just assigns unpredictable device names based on the order of discovery\&. Meaningful symlinks or network device names provide a way to reliably identify devices based on their properties or current configuration\&. -.PP -The udev daemon, -\fBudevd\fR(8), receives device uevents directly from the kernel whenever a device is added or removed from the system, or it changes its state\&. When udev receives a device event, it matches its configured set of rules against various device attributes to identify the device\&. Rules that match may provide additional device information to be stored in the udev database or to be used to create meaningful symlink names\&. -.PP -All device information udev processes is stored in the udev database and sent out to possible event subscribers\&. Access to all stored data and the event sources is provided by the library libudev\&. -.SH "RULES FILES" -.PP -The udev rules are read from the files located in the system rules directory -/usr/lib/udev/rules\&.d, the volatile runtime directory -/run/udev/rules\&.d -and the local administration directory -/etc/udev/rules\&.d\&. All rules files are collectively sorted and processed in lexical order, regardless of the directories in which they live\&. However, files with identical file names replace each other\&. Files in -/etc -have the highest priority, files in -/run -take precedence over files with the same name in -/lib\&. This can be used to override a system\-supplied rules file with a local file if needed; a symlink in -/etc -with the same name as a rules file in -/lib, pointing to -/dev/null, disables the rules file entirely\&. -.PP -Rule files must have the extension -\&.rules; other extensions are ignored\&. -.PP -Every line in the rules file contains at least one key\-value pair\&. Except for empty lines or lines beginning with \*(Aq#\*(Aq, which are ignored\&. There are two kinds of keys: match and assignment\&. If all match keys match against their values, the rule gets applied and the assignment keys get the specified values assigned\&. -.PP -A matching rule may rename a network interface, add symlinks pointing to the device node, or run a specified program as part of the event handling\&. -.PP -A rule consists of a comma\-separated list of one or more key\-value pairs\&. Each key has a distinct operation, depending on the used operator\&. Valid operators are: -.PP -== -.RS 4 -Compare for equality\&. -.RE -.PP -!= -.RS 4 -Compare for inequality\&. -.RE -.PP -= -.RS 4 -Assign a value to a key\&. Keys that represent a list are reset and only this single value is assigned\&. -.RE -.PP -+= -.RS 4 -Add the value to a key that holds a list of entries\&. -.RE -.PP -:= -.RS 4 -Assign a value to a key finally; disallow any later changes\&. -.RE -.PP -The following key names can be used to match against device properties\&. Some of the keys also match against properties of the parent devices in sysfs, not only the device that has generated the event\&. If multiple keys that match a parent device are specified in a single rule, all these keys must match at one and the same parent device\&. -.PP -\fBACTION\fR -.RS 4 -Match the name of the event action\&. -.RE -.PP -\fBDEVPATH\fR -.RS 4 -Match the devpath of the event device\&. -.RE -.PP -\fBKERNEL\fR -.RS 4 -Match the name of the event device\&. -.RE -.PP -\fBNAME\fR -.RS 4 -Match the name of a network interface\&. It can be used once the NAME key has been set in one of the preceding rules\&. -.RE -.PP -\fBSYMLINK\fR -.RS 4 -Match the name of a symlink targeting the node\&. It can be used once a SYMLINK key has been set in one of the preceding rules\&. There may be multiple symlinks; only one needs to match\&. -.RE -.PP -\fBSUBSYSTEM\fR -.RS 4 -Match the subsystem of the event device\&. -.RE -.PP -\fBDRIVER\fR -.RS 4 -Match the driver name of the event device\&. Only set this key for devices which are bound to a driver at the time the event is generated\&. -.RE -.PP -\fBATTR{\fR\fB\fIfilename\fR\fR\fB}\fR -.RS 4 -Match sysfs attribute values of the event device\&. Trailing whitespace in the attribute values is ignored unless the specified match value itself contains trailing whitespace\&. -.RE -.PP -\fBKERNELS\fR -.RS 4 -Search the devpath upwards for a matching device name\&. -.RE -.PP -\fBSUBSYSTEMS\fR -.RS 4 -Search the devpath upwards for a matching device subsystem name\&. -.RE -.PP -\fBDRIVERS\fR -.RS 4 -Search the devpath upwards for a matching device driver name\&. -.RE -.PP -\fBATTRS{\fR\fB\fIfilename\fR\fR\fB}\fR -.RS 4 -Search the devpath upwards for a device with matching sysfs attribute values\&. If multiple -\fBATTRS\fR -matches are specified, all of them must match on the same device\&. Trailing whitespace in the attribute values is ignored unless the specified match value itself contains trailing whitespace\&. -.RE -.PP -\fBTAGS\fR -.RS 4 -Search the devpath upwards for a device with matching tag\&. -.RE -.PP -\fBENV{\fR\fB\fIkey\fR\fR\fB}\fR -.RS 4 -Match against a device property value\&. -.RE -.PP -\fBTAG\fR -.RS 4 -Match against a device tag\&. -.RE -.PP -\fBTEST{\fR\fB\fIoctal mode mask\fR\fR\fB}\fR -.RS 4 -Test the existence of a file\&. An octal mode mask can be specified if needed\&. -.RE -.PP -\fBPROGRAM\fR -.RS 4 -Execute a program to determine whether there is a match; the key is true if the program returns successfully\&. The device properties are made available to the executed program in the environment\&. The program\*(Aqs stdout is available in the RESULT key\&. -.sp -This can only be used for very short\-running foreground tasks\&. For details see -\fBRUN\fR\&. -.RE -.PP -\fBRESULT\fR -.RS 4 -Match the returned string of the last PROGRAM call\&. This key can be used in the same or in any later rule after a PROGRAM call\&. -.RE -.PP -Most of the fields support shell\-style pattern matching\&. The following pattern characters are supported: -.PP -* -.RS 4 -Matches zero or more characters\&. -.RE -.PP -? -.RS 4 -Matches any single character\&. -.RE -.PP -[] -.RS 4 -Matches any single character specified within the brackets\&. For example, the pattern string \*(Aqtty[SR]\*(Aq would match either \*(AqttyS\*(Aq or \*(AqttyR\*(Aq\&. Ranges are also supported via the \*(Aq\-\*(Aq character\&. For example, to match on the range of all digits, the pattern [0\-9] could be used\&. If the first character following the \*(Aq[\*(Aq is a \*(Aq!\*(Aq, any characters not enclosed are matched\&. -.RE -.PP -The following keys can get values assigned: -.PP -\fBNAME\fR -.RS 4 -The name to use for a network interface\&. The name of a device node cannot be changed by udev, only additional symlinks can be created\&. -.RE -.PP -\fBSYMLINK\fR -.RS 4 -The name of a symlink targeting the node\&. Every matching rule adds this value to the list of symlinks to be created\&. -.sp -The set of characters to name a symlink is limited\&. Allowed characters are [0\-9A\-Za\-z#+\-\&.:=@_/], valid utf8 character sequences, and "\ex00" hex encoding\&. All other characters are replaced by a \*(Aq_\*(Aq character\&. -.sp -Multiple symlinks may be specified by separating the names by the space character\&. In case multiple devices claim the same name, the link always points to the device with the highest link_priority\&. If the current device goes away, the links are re\-evaluated and the device with the next highest link_priority becomes the owner of the link\&. If no link_priority is specified, the order of the devices (and which one of them owns the link) is undefined\&. -.sp -Symlink names must never conflict with the kernel\*(Aqs default device node names, as that would result in unpredictable behavior\&. -.RE -.PP -\fBOWNER\fR, \fBGROUP\fR, \fBMODE\fR -.RS 4 -The permissions for the device node\&. Every specified value overrides the compiled\-in default value\&. -.RE -.PP -\fBATTR{\fR\fB\fIkey\fR\fR\fB}\fR -.RS 4 -The value that should be written to a sysfs attribute of the event device\&. -.RE -.PP -\fBENV{\fR\fB\fIkey\fR\fR\fB}\fR -.RS 4 -Set a device property value\&. Property names with a leading \*(Aq\&.\*(Aq are neither stored in the database nor exported to events or external tools (run by, say, the PROGRAM match key)\&. -.RE -.PP -\fBTAG\fR -.RS 4 -Attach a tag to a device\&. This is used to filter events for users of libudev\*(Aqs monitor functionality, or to enumerate a group of tagged devices\&. The implementation can only work efficiently if only a few tags are attached to a device\&. It is only meant to be used in contexts with specific device filter requirements, and not as a general\-purpose flag\&. Excessive use might result in inefficient event handling\&. -.RE -.PP -\fBRUN{\fR\fB\fItype\fR\fR\fB}\fR -.RS 4 -Add a program to the list of programs to be executed after processing all the rules for a specific event, depending on -type: -.PP -program -.RS 4 -Execute an external program specified as the assigned value\&. If no absolute path is given, the program is expected to live in /usr/lib/udev, otherwise the absolute path must be specified\&. -.sp -This is the default if no -\fItype\fR -is specified\&. -.RE -.PP -builtin -.RS 4 -As -\fBprogram\fR, but use one of the built\-in programs rather than an external one\&. -.RE -.sp -The program name and following arguments are separated by spaces\&. Single quotes can be used to specify arguments with spaces\&. -.sp -This can only be used for very short\-running foreground tasks\&. Running an event process for a long period of time may block all further events for this or a dependent device\&. -.sp -Starting daemons or other long running processes is not appropriate for udev; the forked processes, detached or not, will be unconditionally killed after the event handling has finished\&. -.RE -.PP -\fBLABEL\fR -.RS 4 -A named label to which a GOTO may jump\&. -.RE -.PP -\fBGOTO\fR -.RS 4 -Jumps to the next LABEL with a matching name\&. -.RE -.PP -\fBIMPORT{\fR\fB\fItype\fR\fR\fB}\fR -.RS 4 -Import a set of variables as device properties, depending on -type: -.PP -program -.RS 4 -Execute an external program specified as the assigned value and import its output, which must be in environment key format\&. Path specification, command/argument separation, and quoting work like in -\fBRUN\fR\&. -.RE -.PP -builtin -.RS 4 -As -\fBprogram\fR, but use one of the built\-in programs rather than an external one\&. -.RE -.PP -file -.RS 4 -Import a text file specified as the assigned value, the content of which must be in environment key format\&. -.RE -.PP -db -.RS 4 -Import a single property specified as the assigned value from the current device database\&. This works only if the database is already populated by an earlier event\&. -.RE -.PP -cmdline -.RS 4 -Import a single property from the kernel command line\&. For simple flags the value of the property is set to \*(Aq1\*(Aq\&. -.RE -.PP -parent -.RS 4 -Import the stored keys from the parent device by reading the database entry of the parent device\&. The value assigned to -\fBIMPORT{parent}\fR -is used as a filter of key names to import (with the same shell\-style pattern matching used for comparisons)\&. -.RE -.sp -This can only be used for very short\-running foreground tasks\&. For details see -\fBRUN\fR\&. -.RE -.PP -\fBWAIT_FOR\fR -.RS 4 -Wait for a file to become available or until a timeout of 10 seconds expires\&. The path is relative to the sysfs device; if no path is specified, this waits for an attribute to appear\&. -.RE -.PP -\fBOPTIONS\fR -.RS 4 -Rule and device options: -.PP -\fBlink_priority=\fR\fB\fIvalue\fR\fR -.RS 4 -Specify the priority of the created symlinks\&. Devices with higher priorities overwrite existing symlinks of other devices\&. The default is 0\&. -.RE -.PP -\fBevent_timeout=\fR -.RS 4 -Number of seconds an event waits for operations to finish before giving up and terminating itself\&. -.RE -.PP -\fBstring_escape=\fR\fB\fInone|replace\fR\fR -.RS 4 -Usually control and other possibly unsafe characters are replaced in strings used for device naming\&. The mode of replacement can be specified with this option\&. -.RE -.PP -\fBstatic_node=\fR -.RS 4 -Apply the permissions specified in this rule to the static device node with the specified name\&. Static device node creation can be requested by kernel modules\&. These nodes might not have a corresponding kernel device at the time udevd is started; they can trigger automatic kernel module loading\&. -.RE -.PP -\fBwatch\fR -.RS 4 -Watch the device node with inotify; when the node is closed after being opened for writing, a change uevent is synthesized\&. -.RE -.PP -\fBnowatch\fR -.RS 4 -Disable the watching of a device node with inotify\&. -.RE -.RE -.PP -The -\fBNAME\fR, -\fBSYMLINK\fR, -\fBPROGRAM\fR, -\fBOWNER\fR, -\fBGROUP\fR, -\fBMODE\fR -and -\fBRUN\fR -fields support simple string substitutions\&. The -\fBRUN\fR -substitutions are performed after all rules have been processed, right before the program is executed, allowing for the use of device properties set by earlier matching rules\&. For all other fields, substitutions are performed while the individual rule is being processed\&. The available substitutions are: -.PP -\fB$kernel\fR, \fB%k\fR -.RS 4 -The kernel name for this device\&. -.RE -.PP -\fB$number\fR, \fB%n\fR -.RS 4 -The kernel number for this device\&. For example, \*(Aqsda3\*(Aq has kernel number of \*(Aq3\*(Aq -.RE -.PP -\fB$devpath\fR, \fB%p\fR -.RS 4 -The devpath of the device\&. -.RE -.PP -\fB$id\fR, \fB%b\fR -.RS 4 -The name of the device matched while searching the devpath upwards for -\fBSUBSYSTEMS\fR, -\fBKERNELS\fR, -\fBDRIVERS\fR -and -\fBATTRS\fR\&. -.RE -.PP -\fB$driver\fR -.RS 4 -The driver name of the device matched while searching the devpath upwards for -\fBSUBSYSTEMS\fR, -\fBKERNELS\fR, -\fBDRIVERS\fR -and -\fBATTRS\fR\&. -.RE -.PP -\fB$attr{\fR\fB\fIfile\fR\fR\fB}\fR, \fB%s{\fR\fB\fIfile\fR\fR\fB}\fR -.RS 4 -The value of a sysfs attribute found at the device where all keys of the rule have matched\&. If the matching device does not have such an attribute, and a previous KERNELS, SUBSYSTEMS, DRIVERS, or ATTRS test selected a parent device, then the attribute from that parent device is used\&. -.sp -If the attribute is a symlink, the last element of the symlink target is returned as the value\&. -.RE -.PP -\fB$env{\fR\fB\fIkey\fR\fR\fB}\fR, \fB%E{\fR\fB\fIkey\fR\fR\fB}\fR -.RS 4 -A device property value\&. -.RE -.PP -\fB$major\fR, \fB%M\fR -.RS 4 -The kernel major number for the device\&. -.RE -.PP -\fB$minor\fR, \fB%m\fR -.RS 4 -The kernel minor number for the device\&. -.RE -.PP -\fB$result\fR, \fB%c\fR -.RS 4 -The string returned by the external program requested with PROGRAM\&. A single part of the string, separated by a space character, may be selected by specifying the part number as an attribute: -\fB%c{N}\fR\&. If the number is followed by the \*(Aq+\*(Aq character, this part plus all remaining parts of the result string are substituted: -\fB%c{N+}\fR -.RE -.PP -\fB$parent\fR, \fB%P\fR -.RS 4 -The node name of the parent device\&. -.RE -.PP -\fB$name\fR -.RS 4 -The current name of the device\&. If not changed by a rule, it is the name of the kernel device\&. -.RE -.PP -\fB$links\fR -.RS 4 -A space\-separated list of the current symlinks\&. The value is only set during a remove event or if an earlier rule assigned a value\&. -.RE -.PP -\fB$root\fR, \fB%r\fR -.RS 4 -The udev_root value\&. -.RE -.PP -\fB$sys\fR, \fB%S\fR -.RS 4 -The sysfs mount point\&. -.RE -.PP -\fB$devnode\fR, \fB%N\fR -.RS 4 -The name of the device node\&. -.RE -.PP -%% -.RS 4 -The \*(Aq%\*(Aq character itself\&. -.RE -.PP -$$ -.RS 4 -The \*(Aq$\*(Aq character itself\&. -.RE -.SH "SEE ALSO" -.PP -\fBudevd\fR(8), -\fBudevadm\fR(8) |