SYSTEMD.PATH(5) systemd.path SYSTEMD.PATH(5)
NAME
systemd.path - Path unit configuration
SYNOPSIS
path.path
DESCRIPTION
A unit configuration file whose name ends in ".path" encodes
information about a path monitored by systemd, for path-based
activation.
This man page lists the configuration options specific to this unit
type. See systemd.unit(5) for the common options of all unit
configuration files. The common configuration items are configured in
the generic [Unit] and [Install] sections. The path specific
configuration options are configured in the [Path] section.
For each path file, a matching unit file must exist, describing the
unit to activate when the path changes. By default, a service by the
same name as the path (except for the suffix) is activated. Example: a
path file foo.path activates a matching service foo.service. The unit
to activate may be controlled by Unit= (see below).
Internally, path units use the inotify(7) API to monitor file systems.
Due to that, it suffers by the same limitations as inotify, and for
example cannot be used to monitor files or directories changed by other
machines on remote NFS file systems.
If a path unit is beneath another mount point in the file system
hierarchy, a dependency between both units is created automatically.
Unless DefaultDependencies=false is used, path units will implicitly
have dependencies of type Conflicts= and Before= on shutdown.target.
These ensure that path units are terminated cleanly prior to system
shutdown. Only path units involved with early boot or late system
shutdown should disable this option.
OPTIONS
Path files must include a [Path] section, which carries information
about the path(s) it monitors. The options specific to the [Path]
section of path units are the following:
PathExists=, PathExistsGlob=, PathChanged=, PathModified=,
DirectoryNotEmpty=
Defines paths to monitor for certain changes: PathExists= may be
used to watch the mere existence of a file or directory. If the
file specified exists, the configured unit is activated.
PathExistsGlob= works similar, but checks for the existence of at
least one file matching the globbing pattern specified.
PathChanged= may be used to watch a file or directory and activate
the configured unit whenever it changes. It is not activated on
every write to the watched file but it is activated if the file
which was open for writing gets closed. PathModified= is similar,
but additionally it is activated also on simple writes to the
watched file. DirectoryNotEmpty= may be used to watch a directory
and activate the configured unit whenever it contains at least one
file.
The arguments of these directives must be absolute file system
paths.
Multiple directives may be combined, of the same and of different
types, to watch multiple paths. If the empty string is assigned to
any of these options, the list of paths to watch is reset, and any
prior assignments of these options will not have any effect.
If a path already exists (in case of PathExists= and
PathExistsGlob=) or a directory already is not empty (in case of
DirectoryNotEmpty=) at the time the path unit is activated, then
the configured unit is immediately activated as well. Something
similar does not apply to PathChanged= and PathModified=.
If the path itself or any of the containing directories are not
accessible, systemd will watch for permission changes and notice
that conditions are satisfied when permissions allow that.
Unit=
The unit to activate when any of the configured paths changes. The
argument is a unit name, whose suffix is not ".path". If not
specified, this value defaults to a service that has the same name
as the path unit, except for the suffix. (See above.) It is
recommended that the unit name that is activated and the unit name
of the path unit are named identical, except for the suffix.
MakeDirectory=
Takes a boolean argument. If true, the directories to watch are
created before watching. This option is ignored for PathExists=
settings. Defaults to false.
DirectoryMode=
If MakeDirectory= is enabled, use the mode specified here to create
the directories in question. Takes an access mode in octal
notation. Defaults to 0755.
SEE ALSO
systemd(1), systemctl(1), systemd.unit(5), systemd.service(5),
inotify(7), systemd.directives(7)
systemd 219 SYSTEMD.PATH(5)