Provided by: systemd_256.5-2ubuntu3_amd64 bug

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.  --pid=auto 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)