SYSTEMD.PATH(5)                                   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.

          When a service unit triggered by a path unit terminates
          (regardless whether it exited successfully or failed),
          monitored paths are checked immediately again, and the
          service accordingly restarted instantly. As protection
          against busy looping in this trigger/start cycle, a start
          rate limit is enforced on the service unit, see
          StartLimitIntervalSec= and StartLimitBurst= in
          systemd.unit(5). Unlike other service failures, the error
          condition that the start rate limit is hit is propagated
          from the service unit to the path unit and causes the path
          unit to fail as well, thus ending the loop.

     AUTOMATIC DEPENDENCIES
        Implicit Dependencies
          The following dependencies are implicitly added:

          +o   If a path unit is beneath another mount unit in the file
              system hierarchy, both a requirement and an ordering
              dependency between both units are created automatically.

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     SYSTEMD.PATH(5)                                   SYSTEMD.PATH(5)

          +o   An implicit Before= dependency is added between a path
              unit and the unit it is supposed to activate.

        Default Dependencies
          The following dependencies are added unless
          DefaultDependencies=no is set:

          +o   Path units will automatically have dependencies of type
              Before= on paths.target, dependencies of type After= and
              Requires= on sysinit.target, and 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
              DefaultDependencies= 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

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     SYSTEMD.PATH(5)                                   SYSTEMD.PATH(5)

              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)

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