NAME
udevadm - udev management tool
SYNOPSIS
udevadm [--debug] [--version] [--help]
udevadm info options
udevadm trigger [options]
udevadm settle [options]
udevadm control command
udevadm monitor [options]
udevadm test [options] devpath
DESCRIPTION
udevadm expects a command and command specific options. It controls the
runtime behavior of udev, requests kernel events, manages the event
queue, and provides simple debugging mechanisms.
OPTIONS
--debug
Print debug messages to stderr.
--version
Print version number.
--help
Print help text.
udevadm info options
Queries the udev database for device information stored in the udev
database. It can also query the properties of a device from its sysfs
representation to help creating udev rules that match this device.
--query=type
Query the database for specified type of device data. It needs the
--path or --name to identify the specified device. Valid queries
are: name, symlink, path, property, all.
--path=devpath
The devpath of the device to query.
--name=file
The name of the device node or a symlink to query
--root
The udev root directory: /dev. If used in conjunction with a name
or symlink query, the query returns the absolute path including the
root directory.
--attribute-walk
Print all sysfs properties of the specified device that can be used
in udev rules to match the specified device. It prints all devices
along the chain, up to the root of sysfs that can be used in udev
rules.
--device-id-of-file=file
Print major/minor numbers of the underlying device, where the file
lives on.
--export-db
Export the content of the udev database.
--version
Print version.
--help
Print help text.
udevadm trigger [options]
Request device events from the kernel. Primarily used to replay events
at system coldplug time.
--verbose
Print the list of devices which will be triggered.
--dry-run
Do not actually trigger the event.
--type=type
Trigger a specific type of devices. Valid types are: devices,
subsystems, failed. The default value is devices.
--action=action
Type of event to be triggered. The default value is change.
--subsystem-match=subsystem
Trigger events for devices which belong to a matching subsystem.
This option can be specified multiple times and supports shell
style pattern matching.
--subsystem-nomatch=subsystem
Do not trigger events for devices which belong to a matching
subsystem. This option can be specified multiple times and supports
shell style pattern matching.
--attr-match=attribute=value
Trigger events for devices with a matching sysfs attribute. If a
value is specified along with the attribute name, the content of
the attribute is matched against the given value using shell style
pattern matching. If no value is specified, the existence of the
sysfs attribute is checked. This option can be specified multiple
times.
--attr-nomatch=attribute=value
Do not trigger events for devices with a matching sysfs attribute.
If a value is specified along with the attribute name, the content
of the attribute is matched against the given value using shell
style pattern matching. If no value is specified, the existence of
the sysfs attribute is checked. This option can be specified
multiple times.
--property-match=property=value
Trigger events for devices with a matching property value. This
option can be specified multiple times and supports shell style
pattern matching.
--tag-match=property
Trigger events for devices with a matching tag. This option can be
specified multiple times.
--sysname-match=name
Trigger events for devices with a matching sys device name. This
option can be specified multiple times and supports shell style
pattern matching.
udevadm settle [options]
Watches the udev event queue, and exits if all current events are
handled.
--timeout=seconds
Maximum number of seconds to wait for the event queue to become
empty. The default value is 180 seconds. A value of 0 will check if
the queue is empty and always return immediately.
--seq-start=seqnum
Wait only for events after the given sequence number.
--seq-end=seqnum
Wait only for events before the given sequence number.
--exit-if-exists=file
Stop waiting if file exists.
--quiet
Do not print any output, like the remaining queue entries when
reaching the timeout.
--help
Print help text.
udevadm control command
Modify the internal state of the running udev daemon.
--log-priority=value
Set the internal log level of udevd. Valid values are the numerical
syslog priorities or their textual representations: err, info and
debug.
--stop-exec-queue
Signal udevd to stop executing new events. Incoming events will be
queued.
--start-exec-queue
Signal udevd to enable the execution of events.
--reload-rules
Signal udevd to reload the rules files. The udev daemon detects
changes automatically, this option is usually not needed. Reloading
rules does not apply any changes to already existing devices.
--property=KEY=value
Set a global property for all events.
--children-max=value
Set the maximum number of events, udevd will handle at the same
time.
--help
Print help text.
udevadm monitor [options]
Listens to the kernel uevents and events sent out by a udev rule and
prints the devpath of the event to the console. It can be used to
analyze the event timing, by comparing the timestamps of the kernel
uevent and the udev event.
--kernel
Print the kernel uevents.
--udev
Print the udev event after the rule processing.
--property
Also print the properties of the event.
--subsystem-match=string[/string]
Filter events by subsystem[/devtype]. Only udev events with a
matching subsystem value will pass.
--tag-match=string
Filter events by property. Only udev events with a given tag
attached will pass.
--help
Print help text.
udevadm test [options] devpath
Simulate a udev event run for the given device, and print debug output.
--action=string
The action string.
--subsystem=string
The subsystem string.
--help
Print help text.
AUTHOR
Written by Kay Sievers kay.sievers@vrfy.org.
SEE ALSO
udev(7) udevd(8)