systemd.path(5) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | AUTOMATIC DEPENDENCIES | OPTIONS | SEE ALSO | COLOPHON

SYSTEMD.PATH(5)                 systemd.path                 SYSTEMD.PATH(5)

NAME         top

       systemd.path - Path unit configuration

SYNOPSIS         top

       path.path

DESCRIPTION         top

       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         top

   Implicit Dependencies
       The following dependencies are implicitly added:

       ·   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.

       ·   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:

       ·   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         top

       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         top

       systemd(1), systemctl(1), systemd.unit(5), systemd.service(5),
       inotify(7), systemd.directives(7)

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have a bug
       report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2020-07-14.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-07-14.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not part
       of the original manual page), send a mail to man-pages@man7.org

systemd 246                                                  SYSTEMD.PATH(5)

Pages that refer to this page: init(1)systemd(1)systemd.unit(5)30-systemd-environment-d-generator(7)daemon(7)systemd.directives(7)systemd.index(7)systemd.special(7)systemd.syntax(7)