Provided by: systemd_204-5ubuntu20.31_amd64 
NAME
systemd.unit - Unit configuration
SYNOPSIS
service.service, socket.socket, device.device, mount.mount, automount.automount, swap.swap,
target.target, path.path, timer.timer, snapshot.snapshot
/etc/systemd/system/*
/run/systemd/system/*
/usr/lib/systemd/system/*
...
/etc/systemd/user/*
/run/systemd/user/*
/usr/lib/systemd/user/*
...
DESCRIPTION
A unit configuration file encodes information about a service, a socket, a device, a mount point, an
automount point, a swap file or partition, a start-up target, a file system path, or a timer controlled
and supervised by systemd(1). The syntax is inspired by XDG Desktop Entry Specification[1].desktop files,
which are in turn inspired by Microsoft Windows .ini files.
This man page lists the common configuration options of all the unit types. These options need to be
configured in the [Unit] or [Install] sections of the unit files.
In addition to the generic [Unit] and [Install] sections described here, each unit may have a
type-specific section, e.g. [Service] for a service unit. See the respective man pages for more
information: systemd.service(5), systemd.socket(5), systemd.device(5), systemd.mount(5),
systemd.automount(5), systemd.swap(5), systemd.target(5), systemd.path(5), systemd.timer(5),
systemd.snapshot(5).
Unit files are loaded from a set of paths determined during compilation, described in the next section.
Unit files may contain additional options on top of those listed here. If systemd encounters an unknown
option it will write a warning log message but continue loading the unit. If an option is prefixed with
X- it is ignored completely by systemd. Applications may use this to include additional information in
the unit files.
Boolean arguments used in unit files can be written in various formats. For positive settings the strings
1, yes, true and on are equivalent. For negative settings the strings 0, no, false and off are
equivalent.
Time span values encoded in unit files can be written in various formats. A stand-alone number specifies
a time in seconds. If suffixed with a time unit, the unit is honored. A concatenation of multiple values
with units is supported, in which case the values are added up. Example: "50" refers to 50 seconds; "2min
200ms" refers to 2 minutes plus 200 milliseconds, i.e. 120200ms. The following time units are understood:
s, min, h, d, w, ms, us. For details see systemd.time(7).
Empty lines and lines starting with # or ; are ignored. This may be used for commenting. Lines ending in
a backslash are concatenated with the following line while reading and the backslash is replaced by a
space character. This may be used to wrap long lines.
Along with a unit file foo.service the directory foo.service.wants/ may exist. All unit files symlinked
from such a directory are implicitly added as dependencies of type Wanted= to the unit. This is useful to
hook units into the start-up of other units, without having to modify their unit files. For details about
the semantics of Wanted= see below. The preferred way to create symlinks in the .wants/ directory of a
unit file is with the enable command of the systemctl(1) tool which reads information from the [Install]
section of unit files (see below). A similar functionality exists for Requires= type dependencies as
well, the directory suffix is .requires/ in this case.
Along with a unit file foo.service a directory foo.service.d/ may exist. All files with the suffix .conf
from this directory will be parsed after the file itself is parsed. This is useful to alter or add
configuration settings to a unit, without having to modify their unit files. Make sure that the file that
is included has the appropriate section headers before any directive.
If a line starts with .include followed by a file name, the specified file will be parsed at this point.
Make sure that the file that is included has the appropriate section headers before any directives.
Note that while systemd offers a flexible dependency system between units it is recommended to use this
functionality only sparingly and instead rely on techniques such as bus-based or socket-based activation
which make dependencies implicit, resulting in a both simpler and more flexible system.
Some unit names reflect paths existing in the file system name space. Example: a device unit
dev-sda.device refers to a device with the device node /dev/sda in the file system namespace. If this
applies a special way to escape the path name is used, so that the result is usable as part of a file
name. Basically, given a path, "/" is replaced by "-", and all unprintable characters and the "-" are
replaced by C-style "\x20" escapes. The root directory "/" is encoded as single dash, while otherwise the
initial and ending "/" is removed from all paths during transformation. This escaping is reversible.
Optionally, units may be instantiated from a template file at runtime. This allows creation of multiple
units from a single configuration file. If systemd looks for a unit configuration file it will first
search for the literal unit name in the filesystem. If that yields no success and the unit name contains
an @ character, systemd will look for a unit template that shares the same name but with the instance
string (i.e. the part between the @ character and the suffix) removed. Example: if a service
getty@tty3.service is requested and no file by that name is found, systemd will look for getty@.service
and instantiate a service from that configuration file if it is found.
To refer to the instance string from within the configuration file you may use the special %i specifier
in many of the configuration options. See below for details.
If a unit file is empty (i.e. has the file size 0) or is symlinked to /dev/null its configuration will
not be loaded and it appears with a load state of masked, and cannot be activated. Use this as an
effective way to fully disable a unit, making it impossible to start it even manually.
The unit file format is covered by the Interface Stability Promise[2].
UNIT LOAD PATH
Unit files are loaded from a set of paths determined during compilation, described in the two tables
below. Unit files found in directories higher in the hierarchy override files with the same name lower in
the hierarchy, thus allowing overrides.
When systemd is running in user mode (--user) and the variable $SYSTEMD_UNIT_PATH is set, this contents
of this variable overrides the unit load path.
Table 1. Load path when running in system mode (--system).
┌──────────────────────────────┬──────────────────────────────┐
│Path │ Description │
├──────────────────────────────┼──────────────────────────────┤
│/run/systemd/generator.early │ Generated units (early) │
├──────────────────────────────┼──────────────────────────────┤
│/etc/systemd/system │ Local configuration │
├──────────────────────────────┼──────────────────────────────┤
│/run/systemd/systemd │ Volatile units │
├──────────────────────────────┼──────────────────────────────┤
│/run/systemd/generator │ Generated units (middle) │
├──────────────────────────────┼──────────────────────────────┤
│/usr/local/lib/systemd/system │ Units for local packages │
├──────────────────────────────┼──────────────────────────────┤
│/usr/lib/systemd/system │ Units for installed packages │
├──────────────────────────────┼──────────────────────────────┤
│/run/systemd/generator.late │ Generated units (late) │
└──────────────────────────────┴──────────────────────────────┘
Table 2. Load path when running in session mode (--user).
┌────────────────────────────────────┬──────────────────────────────┐
│Path │ Description │
├────────────────────────────────────┼──────────────────────────────┤
│/tmp/systemd-generator.early.XXXXXX │ Generated units (early) │
├────────────────────────────────────┼──────────────────────────────┤
│/etc/systemd/user │ Local configuration │
├────────────────────────────────────┼──────────────────────────────┤
│/run/systemd/user │ Volatile units │
├────────────────────────────────────┼──────────────────────────────┤
│/tmp/systemd-generator.XXXXXX │ Generated units (middle) │
├────────────────────────────────────┼──────────────────────────────┤
│/usr/local/lib/systemd/user │ Units for local packages │
├────────────────────────────────────┼──────────────────────────────┤
│/usr/lib/systemd/user │ Units for installed packages │
├────────────────────────────────────┼──────────────────────────────┤
│/tmp/systemd-generator.late.XXXXXX │ Generated units (late) │
└────────────────────────────────────┴──────────────────────────────┘
Additional units might be loaded into systemd ("linked") from directories not on the unit load path. See
the link command for systemctl(1).
OPTIONS
Unit file may include a [Unit] section, which carries generic information about the unit that is not
dependent on the type of unit:
Description=
A free-form string describing the unit. This is intended for use in UIs to show descriptive
information along with the unit name.
Documentation=
A space separated list of URIs referencing documentation for this unit or its configuration. Accepted
are only URIs of the types http://, https://, file:, info:, man:. For more information about the
syntax of these URIs see uri(7). The URIs should be listed in order of relevance, starting with the
most relevant. It is a good idea to first reference documentation that explains what the unit's
purpose is, followed by how it is configured, followed by any other related documentation. This
option may be specified more than once in which case the specified list of URIs is merged. If the
empty string is assigned to this option the list is reset and all prior assignments will have no
effect.
Requires=
Configures requirement dependencies on other units. If this unit gets activated, the units listed
here will be activated as well. If one of the other units gets deactivated or its activation fails,
this unit will be deactivated. This option may be specified more than once, in which case requirement
dependencies for all listed names are created. Note that requirement dependencies do not influence
the order in which services are started or stopped. This has to be configured independently with the
After= or Before= options. If a unit foo.service requires a unit bar.service as configured with
Requires= and no ordering is configured with After= or Before=, then both units will be started
simultaneously and without any delay between them if foo.service is activated. Often it is a better
choice to use Wants= instead of Requires= in order to achieve a system that is more robust when
dealing with failing services.
Note that dependencies of this type may also be configured outside of the unit configuration file by
adding a symlink to a .requires/ directory accompanying the unit file. For details see above.
RequiresOverridable=
Similar to Requires=. Dependencies listed in RequiresOverridable= which cannot be fulfilled or fail
to start are ignored if the startup was explicitly requested by the user. If the start-up was pulled
in indirectly by some dependency or automatic start-up of units that is not requested by the user
this dependency must be fulfilled and otherwise the transaction fails. Hence, this option may be used
to configure dependencies that are normally honored unless the user explicitly starts up the unit, in
which case whether they failed or not is irrelevant.
Requisite=, RequisiteOverridable=
Similar to Requires= and RequiresOverridable=, respectively. However, if a unit listed here is not
started already it will not be started and the transaction fails immediately.
Wants=
A weaker version of Requires=. A unit listed in this option will be started if the configuring unit
is. However, if the listed unit fails to start up or cannot be added to the transaction this has no
impact on the validity of the transaction as a whole. This is the recommended way to hook start-up of
one unit to the start-up of another unit.
Note that dependencies of this type may also be configured outside of the unit configuration file by
adding a symlink to a .wants/ directory accompanying the unit file. For details see above.
BindsTo=
Configures requirement dependencies, very similar in style to Requires=, however in addition to this
behavior it also declares that this unit is stopped when any of the units listed suddenly disappears.
Units can suddenly, unexpectedly disappear if a service terminates on its own choice, a device is
unplugged or a mount point unmounted without involvement of systemd.
PartOf=
Configures dependencies similar to Requires=, but limited to stopping and restarting of units. When
systemd stops or restarts the units listed here, the action is propagated to this unit. Note that
this is a one way dependency - changes to this unit do not affect the listed units.
Conflicts=
Configures negative requirement dependencies. If a unit has a Conflicts= setting on another unit,
starting the former will stop the latter and vice versa. Note that this setting is independent of and
orthogonal to the After= and Before= ordering dependencies.
If a unit A that conflicts with a unit B is scheduled to be started at the same time as B, the
transaction will either fail (in case both are required part of the transaction) or be modified to be
fixed (in case one or both jobs are not a required part of the transaction). In the latter case the
job that is not the required will be removed, or in case both are not required the unit that
conflicts will be started and the unit that is conflicted is stopped.
Before=, After=
Configures ordering dependencies between units. If a unit foo.service contains a setting
Before=bar.service and both units are being started, bar.service's start-up is delayed until
foo.service is started up. Note that this setting is independent of and orthogonal to the requirement
dependencies as configured by Requires=. It is a common pattern to include a unit name in both the
After= and Requires= option in which case the unit listed will be started before the unit that is
configured with these options. This option may be specified more than once, in which case ordering
dependencies for all listed names are created. After= is the inverse of Before=, i.e. while After=
ensures that the configured unit is started after the listed unit finished starting up, Before=
ensures the opposite, i.e. that the configured unit is fully started up before the listed unit is
started. Note that when two units with an ordering dependency between them are shut down, the inverse
of the start-up order is applied. i.e. if a unit is configured with After= on another unit, the
former is stopped before the latter if both are shut down. If one unit with an ordering dependency on
another unit is shut down while the latter is started up, the shut down is ordered before the
start-up regardless whether the ordering dependency is actually of type After= or Before=. If two
units have no ordering dependencies between them they are shut down or started up simultaneously, and
no ordering takes place.
OnFailure=
Lists one or more units that are activated when this unit enters the 'failed' state.
PropagatesReloadTo=, ReloadPropagatedFrom=
Lists one or more units where reload requests on the unit will be propagated to/on the other unit
will be propagated from. Issuing a reload request on a unit will automatically also enqueue a reload
request on all units that the reload request shall be propagated to via these two settings.
RequiresMountsFor=
Takes a space separated list of absolute paths. Automatically adds dependencies of type Requires= and
After= for all mount units required to access the specified path.
OnFailureIsolate=
Takes a boolean argument. If true the unit listed in OnFailure= will be enqueued in isolation mode,
i.e. all units that are not its dependency will be stopped. If this is set only a single unit may be
listed in OnFailure=. Defaults to false.
IgnoreOnIsolate=
Takes a boolean argument. If true this unit will not be stopped when isolating another unit. Defaults
to false.
IgnoreOnSnapshot=
Takes a boolean argument. If true this unit will not be included in snapshots. Defaults to true for
device and snapshot units, false for the others.
StopWhenUnneeded=
Takes a boolean argument. If true this unit will be stopped when it is no longer used. Note that in
order to minimize the work to be executed, systemd will not stop units by default unless they are
conflicting with other units, or the user explicitly requested their shut down. If this option is
set, a unit will be automatically cleaned up if no other active unit requires it. Defaults to false.
RefuseManualStart=, RefuseManualStop=
Takes a boolean argument. If true this unit can only be activated or deactivated indirectly. In this
case explicit start-up or termination requested by the user is denied, however if it is started or
stopped as a dependency of another unit, start-up or termination will succeed. This is mostly a
safety feature to ensure that the user does not accidentally activate units that are not intended to
be activated explicitly, and not accidentally deactivate units that are not intended to be
deactivated. These options default to false.
AllowIsolate=
Takes a boolean argument. If true this unit may be used with the systemctl isolate command. Otherwise
this will be refused. It probably is a good idea to leave this disabled except for target units that
shall be used similar to runlevels in SysV init systems, just as a precaution to avoid unusable
system states. This option defaults to false.
DefaultDependencies=
Takes a boolean argument. If true (the default), a few default dependencies will implicitly be
created for the unit. The actual dependencies created depend on the unit type. For example, for
service units, these dependencies ensure that the service is started only after basic system
initialization is completed and is properly terminated on system shutdown. See the respective man
pages for details. Generally, only services involved with early boot or late shutdown should set this
option to false. It is highly recommended to leave this option enabled for the majority of common
units. If set to false this option does not disable all implicit dependencies, just non-essential
ones.
JobTimeoutSec=
When clients are waiting for a job of this unit to complete, time out after the specified time. If
this time limit is reached the job will be cancelled, the unit however will not change state or even
enter the 'failed' mode. This value defaults to 0 (job timeouts disabled), except for device units.
NB: this timeout is independent from any unit-specific timeout (for example, the timeout set with
Timeout= in service units) as the job timeout has no effect on the unit itself, only on the job that
might be pending for it. Or in other words: unit-specific timeouts are useful to abort unit state
changes, and revert them. The job timeout set with this option however is useful to abort only the
job waiting for the unit state to change.
ConditionPathExists=, ConditionPathExistsGlob=, ConditionPathIsDirectory=, ConditionPathIsSymbolicLink=,
ConditionPathIsMountPoint=, ConditionPathIsReadWrite=, ConditionDirectoryNotEmpty=,
ConditionFileNotEmpty=, ConditionFileIsExecutable=, ConditionKernelCommandLine=,
ConditionVirtualization=, ConditionSecurity=, ConditionCapability=, ConditionHost=, ConditionACPower=,
ConditionNull=
Before starting a unit verify that the specified condition is true. If it is not true the starting of
the unit will be skipped, however all ordering dependencies of it are still respected. A failing
condition will not result in the unit being moved into a failure state. The condition is checked at
the time the queued start job is to be executed.
With ConditionPathExists= a file existence condition is checked before a unit is started. If the
specified absolute path name does not exist the condition will fail. If the absolute path name passed
to ConditionPathExists= is prefixed with an exclamation mark ('!'), the test is negated, and the unit
is only started if the path does not exist.
ConditionPathExistsGlob= is similar to ConditionPathExists=, but checks for the existence of at least
one file or directory matching the specified globbing pattern.
ConditionPathIsDirectory= is similar to ConditionPathExists= but verifies whether a certain path
exists and is a directory.
ConditionPathIsSymbolicLink= is similar to ConditionPathExists= but verifies whether a certain path
exists and is a symbolic link.
ConditionPathIsMountPoint= is similar to ConditionPathExists= but verifies whether a certain path
exists and is a mount point.
ConditionPathIsReadWrite= is similar to ConditionPathExists= but verifies whether the underlying file
system is readable and writable (i.e. not mounted read-only).
ConditionDirectoryNotEmpty= is similar to ConditionPathExists= but verifies whether a certain path
exists and is a non-empty directory.
ConditionFileNotEmpty= is similar to ConditionPathExists= but verifies whether a certain path exists
and refers to a regular file with a non-zero size.
ConditionFileIsExecutable= is similar to ConditionPathExists= but verifies whether a certain path
exists, is a regular file and marked executable.
Similar, ConditionKernelCommandLine= may be used to check whether a specific kernel command line
option is set (or if prefixed with the exclamation mark unset). The argument must either be a single
word, or an assignment (i.e. two words, separated '='). In the former case the kernel command line is
searched for the word appearing as is, or as left hand side of an assignment. In the latter case the
exact assignment is looked for with right and left hand side matching.
ConditionVirtualization= may be used to check whether the system is executed in a virtualized
environment and optionally test whether it is a specific implementation. Takes either boolean value
to check if being executed in any virtualized environment, or one of vm and container to test against
a generic type of virtualization solution, or one of qemu, kvm, vmware, microsoft, oracle, xen,
bochs, chroot, openvz, lxc, lxc-libvirt, systemd-nspawn to test against a specific implementation. If
multiple virtualization technologies are nested only the innermost is considered. The test may be
negated by prepending an exclamation mark.
ConditionSecurity= may be used to check whether the given security module is enabled on the system.
Currently the only recognized values are selinux, apparmor, and smack. The test may be negated by
prepending an exclamation mark.
ConditionCapability= may be used to check whether the given capability exists in the capability
bounding set of the service manager (i.e. this does not check whether capability is actually
available in the permitted or effective sets, see capabilities(7) for details). Pass a capability
name such as CAP_MKNOD, possibly prefixed with an exclamation mark to negate the check.
ConditionHost= may be used to match against the host name or machine ID of the host. This either
takes a host name string (optionally with shell style globs) which is tested against the locally set
host name as returned by gethostname(2), or a machine ID formatted as string (see machine-id(5)). The
test may be negated by prepending an exclamation mark.
ConditionACPower= may be used to check whether the system has AC power, or is exclusively battery
powered at the time of activation of the unit. This takes a boolean argument. If set to true the
condition will hold only if at least one AC connector of the system is connected to a power source,
or if no AC connectors are known. Conversely, if set to false the condition will hold only if there
is at least one AC connector known and all AC connectors are disconnected from a power source.
Finally, ConditionNull= may be used to add a constant condition check value to the unit. It takes a
boolean argument. If set to false the condition will always fail, otherwise succeed.
If multiple conditions are specified the unit will be executed if all of them apply (i.e. a logical
AND is applied). Condition checks can be prefixed with a pipe symbol (|) in which case a condition
becomes a triggering condition. If at least one triggering condition is defined for a unit then the
unit will be executed if at least one of the triggering conditions apply and all of the
non-triggering conditions. If you prefix an argument with the pipe symbol and an exclamation mark the
pipe symbol must be passed first, the exclamation second. Except for ConditionPathIsSymbolicLink=,
all path checks follow symlinks. If any of these options is assigned the empty string the list of
conditions is reset completely, all previous condition settings (of any kind) will have no effect.
SourcePath=
A path to a configuration file this unit has been generated from. This is primarily useful for
implementation of generator tools that convert configuration from an external configuration file
format into native unit files. Thus functionality should not be used in normal units.
Unit file may include a [Install] section, which carries installation information for the unit. This
section is not interpreted by systemd(1) during runtime. It is used exclusively by the enable and disable
commands of the systemctl(1) tool during installation of a unit:
Alias=
Additional names this unit shall be installed under. The names listed here must have the same suffix
(i.e. type) as the unit file name. This option may be specified more than once, in which case all
listed names are used. At installation time, systemctl enable will create symlinks from these names
to the unit file name.
WantedBy=, RequiredBy=
Installs a symlink in the .wants/ or .requires/ subdirectory for a unit, respectively. This has the
effect that when the listed unit name is activated the unit listing it is activated too.
WantedBy=foo.service in a service bar.service is mostly equivalent to
Alias=foo.service.wants/bar.service in the same file.
Also=
Additional units to install/deinstall when this unit is installed/deinstalled. If the user requests
installation/deinstallation of a unit with this option configured, systemctl enable and systemctl
disable will automatically install/uninstall units listed in this option as well.
The following specifiers are interpreted in the Install section: %n, %N, %p, %i, %U, %u, %m, %H, %b. For
their meaning see the next section.
SPECIFIERS
Many settings resolve specifiers which may be used to write generic unit files referring to runtime or
unit parameters that are replaced when the unit files are loaded. The following specifiers are
understood:
Table 3. Specifiers available in unit files
┌──────────┬───────────────────────────┬──────────────────────────────┐
│Specifier │ Meaning │ Details │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%n │ Full unit name │ │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%N │ Unescaped full unit name │ │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%p │ Prefix name │ For instantiated units this │
│ │ │ refers to the string before │
│ │ │ the @. For non-instantiated │
│ │ │ units this refers to to the │
│ │ │ name of the unit with the │
│ │ │ type suffix removed. │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%P │ Unescaped prefix name │ │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%i │ Instance name │ For instantiated units: this │
│ │ │ is the string between the @ │
│ │ │ character and the suffix. │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%I │ Unescaped instance name │ │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%f │ Unescaped file name │ This is either the unescaped │
│ │ │ instance name (if │
│ │ │ applicable) with / prepended │
│ │ │ (if applicable), or the │
│ │ │ prefix name similarly │
│ │ │ prepended with /. │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%c │ Control group path of the │ │
│ │ unit │ │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%r │ Root control group path │ For system instances this │
│ │ where units are placed. │ usually resolves to /system, │
│ │ │ except in containers, where │
│ │ │ the path might be prefixed │
│ │ │ with the container's root │
│ │ │ control group. │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%R │ Parent directory of the │ For system instances this │
│ │ control group path where │ usually resolves to /, │
│ │ units are placed. │ except in containers, where │
│ │ │ this resolves to the │
│ │ │ container's root directory. │
│ │ │ This specifier is │
│ │ │ particularly useful in the │
│ │ │ ControlGroup= setting (see │
│ │ │ systemd.exec(5)). │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%t │ Runtime socket dir │ This is either /run (for the │
│ │ │ system manager) or │
│ │ │ $XDG_RUNTIME_DIR (for user │
│ │ │ managers). │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%u │ User name │ This is the name of the │
│ │ │ configured user of the unit, │
│ │ │ or (if none is set) the user │
│ │ │ running the systemd │
│ │ │ instance. │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%U │ User UID │ This is the UID of the │
│ │ │ configured user of the unit, │
│ │ │ or (if none is set) the user │
│ │ │ running the systemd │
│ │ │ instance. │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%h │ User home directory │ This is the home directory │
│ │ │ of the configured user of │
│ │ │ the unit, or (if none is │
│ │ │ set) the user running the │
│ │ │ systemd instance. │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%s │ User shell │ This is the shell of the │
│ │ │ configured user of the unit, │
│ │ │ or (if none is set) the user │
│ │ │ running the systemd │
│ │ │ instance. If the user is │
│ │ │ root (UID equal to 0), the │
│ │ │ shell configured in account │
│ │ │ database is ignored and │
│ │ │ /bin/sh is always used. │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%m │ Machine ID │ The machine ID of the │
│ │ │ running system, formatted as │
│ │ │ string. See machine-id(5) │
│ │ │ for more information. │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%b │ Boot ID │ The boot ID of the running │
│ │ │ system, formatted as string. │
│ │ │ See random(4) for more │
│ │ │ information. │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%H │ Host name │ The host name of the running │
│ │ │ system. │
├──────────┼───────────────────────────┼──────────────────────────────┤
│%% │ Escaped % │ Single percent sign. │
└──────────┴───────────────────────────┴──────────────────────────────┘
SEE ALSO
systemd(1), systemctl(8), systemd.special(7), systemd.service(5), systemd.socket(5), systemd.device(5),
systemd.mount(5), systemd.automount(5), systemd.swap(5), systemd.target(5), systemd.path(5),
systemd.timer(5), systemd.snapshot(5), systemd.time(7), capabilities(7), systemd.directives(7)
NOTES
1. XDG Desktop Entry Specification
http://standards.freedesktop.org/desktop-entry-spec/latest/
2. Interface Stability Promise
http://www.freedesktop.org/wiki/Software/systemd/InterfaceStabilityPromise