X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.unit.xml;h=f6a0791bf98b5f2cac59274087619f498ed55a80;hp=f72b947dca052ffefc7fe99d0eb344638a9b829d;hb=6577c7cea72f19185ad999c223bcf663c010dc6f;hpb=9fc507041eb524799a0410839e961ec188a78491
diff --git a/man/systemd.unit.xml b/man/systemd.unit.xml
index f72b947dc..f6a0791bf 100644
--- a/man/systemd.unit.xml
+++ b/man/systemd.unit.xml
@@ -1,6 +1,9 @@
+ "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
+
+%entities;
+]>
@@ -44,20 +47,32 @@
systemd.unit
- systemd unit configuration files
+ Unit configuration
- systemd.service,
- systemd.socket,
- systemd.device,
- systemd.mount,
- systemd.automount,
- systemd.swap,
- systemd.target,
- systemd.path,
- systemd.timer,
- systemd.snapshot
+ 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/*
+...
+
@@ -66,7 +81,7 @@
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
+ target, a file system path, or a timer controlled and
supervised by
systemd1. The
syntax is inspired by .ini files.
- This man pages lists the common configuration
+ This man page lists the common configuration
options of all the unit types. These options need to
- be configured in the [Unit] resp. [Install]
- section of the unit files.
+ 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 should have a
+ 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.
+ information:
+ systemd.service5,
+ systemd.socket5,
+ systemd.device5,
+ systemd.mount5,
+ systemd.automount5,
+ systemd.swap5,
+ systemd.target5,
+ systemd.path5,
+ systemd.timer5,
+ systemd.snapshot5.
+
+
+ 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
@@ -106,12 +136,14 @@
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
+ 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.
+ are understood: s, min, h, d, w, ms, us. For details
+ see
+ systemd.time7.Empty lines and lines starting with # or ; are
ignored. This may be used for commenting. Lines ending
@@ -119,43 +151,56 @@
line while reading and the backslash is replaced by a
space character. This may be used to wrap long lines.
- If a line starts with
- followed by a file name, the specified file will be
- read as if its contents were listed in place of the
- directive.
-
Along with a unit file
- foo.service a directory
+ foo.service the directory
foo.service.wants/ may exist. All
- units symlinked from such a directory are implicitly
- added as dependencies of type
+ 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 configuration
- files. For details about the semantics of
- Wanted= see below. The preferred
- way to create symlinks in the
- .wants/ directory of a service is
- with the enable command of the
+ 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
systemctl1
tool which reads information from the [Install]
- section of unit files. (See below.)
+ 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
+ followed by a filename, 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 sparsely and instead rely
+ use this functionality only sparingly and instead rely
on techniques such as bus-based or socket-based
- activation which makes dependencies implicit, which
- both results in a simpler and more flexible
- system.
+ 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
+ file system namespace. Example: a device unit
dev-sda.device refers to a device
- with the device node /dev/sda in
+ 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,
+ result is usable as part of a filename. Basically,
given a path, "/" is replaced by "-", and all
unprintable characters and the "-" are replaced by
C-style "\x20" escapes. The root directory "/" is
@@ -169,30 +214,20 @@
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
+ 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
+ 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
+ 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. Other specifiers that may be
- used are %n, %N,
- %p, %P,
- %I and %f, for
- the full unit name, the unescaped unit name, the
- prefix name, the unescaped prefix name, the unescaped
- instance name and the unescaped filename,
- respectively. The unescaped filename is either the
- unescaped instance name (if set) with / prepended (if
- necessary), or the prefix name similarly prepended
- with /. The prefix name here refers to the string
- before the @, i.e. "getty" in the example above, where
- "tty3" is the instance name.
+ 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
@@ -206,6 +241,125 @@
Interface
Stability Promise.
+
+
+
+
+ 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
+ () and the variable
+ $SYSTEMD_UNIT_PATH is set, this
+ contents of this variable overrides the unit load
+ path.
+
+
+
+
+ Load path when running in system mode (<option>--system</option>).
+
+
+
+
+
+
+
+ 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)
+
+
+
+
+
+
+
+ Load path when running in session mode (<option>--user</option>).
+
+
+
+
+
+
+
+ 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
+ systemctl1.
+
@@ -215,22 +369,7 @@
carries generic information about the unit that is not
dependent on the type of unit:
-
-
- Names=
-
- Additional names for
- this unit. 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. Note
- that this option is different from the
- Alias= option from
- the [Install] section mentioned
- below. See below for details.
-
-
+ Description=
@@ -241,6 +380,36 @@
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
+ uri7. 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=
@@ -278,9 +447,16 @@
Requires= in order
to achieve a system that is more
robust when dealing with failing
- services.
-
+ 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=
@@ -311,7 +487,7 @@
Similar to
Requires=
- resp. RequiresOverridable=. However,
+ and RequiresOverridable=, respectively. However,
if a unit listed here is not started
already it will not be started and the
transaction fails
@@ -331,7 +507,9 @@
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
+ unit.
+
+ Note that dependencies of this
type may also be configured outside of
the unit configuration file by
adding a symlink to a
@@ -340,6 +518,38 @@
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=
@@ -425,7 +635,7 @@
Before=. If two
units have no ordering dependencies
between them they are shut down
- resp. started up simultaneously, and
+ or started up simultaneously, and
no ordering takes
place.
@@ -436,30 +646,76 @@
Lists one or more
units that are activated when this
unit enters the
- 'failed'
+ failed
state.
- RecursiveStop=
+ 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 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
+ .
+
+
+
+ IgnoreOnIsolate=Takes a boolean
- argument. If and
- the unit stops without being requested
- by the user, all units
- depending on it will be stopped as
- well. (e.g. if a service exits or
- crashes on its own behalf, units using
- it will be stopped) Note that normally
- if a unit stops without a user request,
- units depending on it will not be
- terminated. Only if the user requested
- shutdown of a unit, all units depending
- on that unit will be shut down as well
- and at the same time. Defaults to
+ argument. If
+ this unit will not be stopped when
+ isolating another unit. Defaults to
.
+
+ IgnoreOnSnapshot=
+
+ Takes a boolean
+ argument. If
+ this unit will not be included in
+ snapshots. Defaults to
+ for device and
+ snapshot units,
+ for the others.
+
+
StopWhenUnneeded=
@@ -485,13 +741,13 @@
Takes a boolean
argument. If
this unit can only be activated
- (resp. deactivated) indirectly. In
+ or deactivated indirectly. In
this case explicit start-up
- (resp. termination) requested by the
+ or termination requested by the
user is denied, however if it is
- started (resp. stopped) as a
+ started or stopped as a
dependency of another unit, start-up
- (resp. termination) will succeed. This
+ or termination will succeed. This
is mostly a safety feature to ensure
that the user does not accidentally
activate units that are not intended
@@ -541,26 +797,12 @@
highly recommended to leave this
option enabled for the majority of
common units. If set to
- this option
+ , this option
does not disable all implicit
dependencies, just non-essential
ones.
-
- IgnoreDependencyFailure=
-
- Takes a boolean
- argument. If and
- a requirement dependency of this unit
- fails to start up this unit will be
- started nonetheless, ignoring that
- failure. If
- (the default) and a dependency unit
- fails the unit will immediately fail
- too and the job is removed.
-
-
JobTimeoutSec=
@@ -570,7 +812,7 @@
time. If this time limit is reached
the job will be cancelled, the unit
however will not change state or even
- enter the 'failed'
+ enter the failed
mode. This value defaults to 0 (job
timeouts disabled), except for device
units. NB: this timeout is independent
@@ -591,45 +833,255 @@
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. With
+ 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 existance condition can be
+ a file existence condition is
checked before a unit is started. If
the specified absolute path name does
- not exist startup of a unit will not
- actually happen, however the unit is
- still useful for ordering purposes in
- this case. The condition is checked at
- the time the queued start job is to be
- executed. If the absolute path name
- passed to
+ 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
- only started if the path does not
- exist. Similarly
+ (!), 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, seperated
- by the equality sign). In the former
- case the kernel command line is search
- 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. If multiple conditions
- are specified the unit will be
- executed iff at least one of them
- apply (i.e. a logical OR is
- applied).
+ 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,
+ uml,
+ 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 recognized values
+ values are selinux,
+ apparmor,
+ ima 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
+ capabilities7
+ 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
+ hostname or machine ID of the
+ host. This either takes a hostname
+ string (optionally with shell style
+ globs) which is tested against the
+ locally set hostname as returned by
+ gethostname2,
+ or a machine ID formatted as string
+ (see
+ machine-id5).
+ 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.
@@ -643,7 +1095,7 @@
systemctl1
tool during installation of a unit:
-
+ Alias=
@@ -657,64 +1109,203 @@
time,
systemctl enable
will create symlinks from these names
- to the unit file name. Note that this
- is different from the
- Names= option from
- the [Unit] section mentioned above:
- The names from
- Names= apply
- unconditionally if the unit is
- loaded. The names from
- Alias= apply only
- if the unit has actually been
- installed with the
- systemctl enable
- command. Also, if systemd searches for a
- unit, it will discover symlinked alias
- names as configured with
- Alias=, but not
- names configured with
- Names= only. It is
- a common pattern to list a name in
- both options. In this case, a unit
- will be active under all names if
- installed, but also if not installed
- but requested explicitly under its
- main name.
+ to the unit filename.
WantedBy=
-
- Installs a symlink in
- the .wants/
- subdirectory for a unit. This has the
- effect that when the listed unit name
- is activated the unit listing it is
- activated
- too. WantedBy=foo.service
+ RequiredBy=
+
+ A symbolic link is
+ created in the
+ .wants/ or
+ .requires/ directory
+ of the listed unit when this unit is
+ activated by systemctl
+ enable. This has the effect
+ that a dependency of type
+ Wants= or
+ Requires= is added
+ from the listed unit to the current
+ unit. The primary result is that the
+ current unit will be started when the
+ listed unit is started. See the
+ description of
+ Wants= and
+ Requires= in the
+ [Unit] section for details.
+
+ WantedBy=foo.service
in a service
bar.service is
mostly equivalent to
Alias=foo.service.wants/bar.service
- in the same file.
+ in the same file. In case of template
+ units, systemctl enable
+ must be called with an instance name, and
+ this instance will be added to the
+ .wants/ or
+ .requires/ list
+ of the listed unit.
+ E.g. WantedBy=getty.target
+ in a service
+ getty@.service
+ will result in systemctl
+ enable getty@tty2.service
+ creating a
+ getty.target.wants/getty@tty2.service
+ link to getty@.service.
+ Also=Additional units to
- install when this unit is
- installed. If the user requests
- installation of a unit with this
- option configured,
+ install/deinstall when this unit is
+ installed/deinstalled. If the user
+ requests installation/deinstallation
+ of a unit with this option configured,
systemctl enable
- will automatically install units
- listed in this option as
+ 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, %v.
+ 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:
+
+
+ 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 filename
+ 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 where units are placed.
+ For system instances this 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 control group path where units are placed.
+ For system instances this usually resolves to /, except in containers, where this resolves to the container's root directory. This specifier is particularly useful in the ControlGroup= setting (see systemd.exec5).
+
+
+ %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-id5 for more information.
+
+
+ %b
+ Boot ID
+ The boot ID of the running system, formatted as string. See random4 for more information.
+
+
+ %H
+ Host name
+ The hostname of the running system.
+
+
+ %v
+ Kernel release
+ Identical to uname -r output.
+
+
+ %%
+ Escaped %
+ Single percent sign.
+
+
+
+