man > systemd-notify(1)

SYSTEMD-NOTIFY(1)                          systemd-notify                          SYSTEMD-NOTIFY(1)

NAME
       systemd-notify - Notify service manager about start-up completion and other daemon status
       changes

SYNOPSIS


       systemd-notify [OPTIONS...] [VARIABLE=VALUE...]

       systemd-notify --exec [OPTIONS...] [VARIABLE=VALUE...] ; [CMDLINE...]

DESCRIPTION
       systemd-notify may be called by service scripts to notify the invoking service manager about
       status changes. It can be used to send arbitrary information, encoded in an
       environment-block-like list of strings. Most importantly, it can be used for start-up
       completion notification.

       This is mostly just a wrapper around sd_notify() and makes this functionality available to
       shell scripts. For details see sd_notify(3).

       The command line may carry a list of environment variables to send as part of the status
       update.

       Note that systemd will refuse reception of status updates from this command unless
       NotifyAccess= is appropriately set for the service unit this command is called from. See
       systemd.service(5) for details.

       Note that sd_notify() notifications may be attributed to units correctly only if either the
       sending process is still around at the time the service manager processes the message, or if
       the sending process is explicitly runtime-tracked by the service manager. The latter is the
       case if the service manager originally forked off the process, i.e. on all processes that
       match NotifyAccess=main or NotifyAccess=exec. Conversely, if an auxiliary process of the unit
       sends an sd_notify() message and immediately exits, the service manager might not be able to
       properly attribute the message to the unit, and thus will ignore it, even if NotifyAccess=all
       is set for it. To address this systemd-notify will wait until the notification message has
       been processed by the service manager. When --no-block is used, this synchronization for
       reception of notifications is disabled, and hence the aforementioned race may occur if the
       invoking process is not the service manager or spawned by the service manager.

       systemd-notify will first attempt to invoke sd_notify() pretending to have the PID of the
       parent process of systemd-notify (i.e. the invoking process). This will only succeed when
       invoked with sufficient privileges. On failure, it will then fall back to invoking it under
       its own PID. This behaviour is useful in order that when the tool is invoked from a shell
       script the shell process — and not the systemd-notify process — appears as sender of the
       message, which in turn is helpful if the shell process is the main process of a service, due
       to the limitations of NotifyAccess=all. Use the --pid= switch to tweak this behaviour.

OPTIONS
       The following options are understood:

       --ready
           Inform the invoking service manager about service start-up or configuration reload
           completion. This is equivalent to systemd-notify READY=1. For details about the semantics
           of this option see sd_notify(3).

       --reloading
           Inform the invoking service manager about the beginning of a configuration reload cycle.
           This is equivalent to systemd-notify RELOADING=1 (but implicitly also sets a
           MONOTONIC_USEC= field as required for Type=notify-reload services, see systemd.service(5)
           for details). For details about the semantics of this option see sd_notify(3).

           Added in version 253.

       --stopping
           Inform the invoking service manager about the beginning of the shutdown phase of the
           service. This is equivalent to systemd-notify STOPPING=1. For details about the semantics
           of this option see sd_notify(3).

           Added in version 253.

       --pid=
           Inform the service manager about the main PID of the service. Takes a PID as argument. If
           the argument is specified as "auto" or omitted, the PID of the process that invoked
           systemd-notify is used, except if that's the service manager. If the argument is
           specified as "self", the PID of the systemd-notify command itself is used, and if
           "parent" is specified the calling process' PID is used — even if it is the service
           manager. The latter is equivalent to systemd-notify MAINPID=$PID. For details about the
           semantics of this option see sd_notify(3).

           If this switch is used in an systemd-notify invocation from a process that shall become
           the new main process of a service — and which is not the process forked off by the
           service manager (or the current main process) —, then it is essential to set
           NotifyAccess=all in the service unit file, or otherwise the notification will be ignored
           for security reasons. See systemd.service(5) for details.

       --uid=USER
           Set the user ID to send the notification from. Takes a UNIX user name or numeric UID.
           When specified the notification message will be sent with the specified UID as sender, in
           place of the user the command was invoked as. This option requires sufficient privileges
           in order to be able manipulate the user identity of the process.

           Added in version 237.

       --status=
           Send a free-form human readable status string for the daemon to the service manager. This
           option takes the status string as argument. This is equivalent to systemd-notify
           STATUS=.... For details about the semantics of this option see sd_notify(3). This
           information is shown in systemctl(1)'s status output, among other places.

       --booted
           Returns 0 if the system was booted up with systemd, non-zero otherwise. If this option is
           passed, no message is sent. This option is hence unrelated to the other options. For
           details about the semantics of this option, see sd_booted(3). An alternate way to check
           for this state is to call systemctl(1) with the is-system-running command. It will return
           "offline" if the system was not booted with systemd.

       --no-block
           Do not synchronously wait for the requested operation to finish. Use of this option is
           only recommended when systemd-notify is spawned by the service manager, or when the
           invoking process is directly spawned by the service manager and has enough privileges to
           allow systemd-notify to send the notification on its behalf. Sending notifications with
           this option set is prone to race conditions in all other cases.

           Added in version 246.

       --exec
           If specified systemd-notify will execute another command line after it completed its
           operation, replacing its own process. If used, the list of assignments to include in the
           message sent must be followed by a ";" character (as separate argument), followed by the
           command line to execute. This permits "chaining" of commands, i.e. issuing one operation,
           followed immediately by another, without changing PIDs.

           Note that many shells interpret ";" as their own separator for command lines, hence when
           systemd-notify is invoked from a shell the semicolon must usually be escaped as "\;".

           Added in version 254.

       --fd=
           Send a file descriptor along with the notification message. This is useful when invoked
           in services that have the FileDescriptorStoreMax= setting enabled, see systemd.service(5)
           for details. The specified file descriptor must be passed to systemd-notify when invoked.
           This option may be used multiple times to pass multiple file descriptors in a single
           notification message.

           To use this functionality from a bash(1) shell, use an expression like the following:

               systemd-notify --fd=4 --fd=5 4</some/file 5</some/other/file

           Added in version 254.

       --fdname=
           Set a name to assign to the file descriptors passed via --fd= (see above). This controls
           the "FDNAME=" field. This setting may only be specified once, and applies to all file
           descriptors passed. Invoke this tool multiple times in case multiple file descriptors
           with different file descriptor names shall be submitted.

           Added in version 254.

       -h, --help
           Print a short help text and exit.

       --version
           Print a short version string and exit.

EXIT STATUS
       On success, 0 is returned, a non-zero failure code otherwise.

EXAMPLE
       Example 1. Start-up Notification and Status Updates

       A simple shell daemon that sends start-up notifications after having set up its communication
       channel. During runtime it sends further status updates to the init system:

           #!/bin/sh

           mkfifo /tmp/waldo
           systemd-notify --ready --status="Waiting for data..."

           while : ; do
                   read -r a < /tmp/waldo
                   systemd-notify --status="Processing $a"

                   # Do something with $a ...

                   systemd-notify --status="Waiting for data..."
           done

SEE ALSO
       systemd(1), systemctl(1), systemd.unit(5), systemd.service(5), sd_notify(3), sd_booted(3)

systemd 255                                                                        SYSTEMD-NOTIFY(1)