systemd-notify — Notify service manager about start-up completion and other daemon status changes
systemd-notify [OPTIONS...] [VARIABLE=VALUE...]
systemd-notify may be called by daemon scripts to notify the init system 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=all is
set for the service unit this command is called from.
The following options are understood:
--ready¶Inform the init system about service start-up completion. This is equivalent to systemd-notify READY=1. For details about the semantics of this option see sd_notify(3).
--pid=¶Inform the init system about the main PID of the daemon. Takes a PID as argument. If the argument is omitted, the PID of the process that invoked systemd-notify is used. This is equivalent to systemd-notify MAINPID=$PID. For details about the semantics of this option see sd_notify(3).
--status=¶Send a free-form status string for the daemon to the init systemd. 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).
--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.
-h, --help¶--version¶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/bash
mkfifo /tmp/waldo
systemd-notify --ready --status="Waiting for data..."
while : ; do
read a < /tmp/waldo
systemd-notify --status="Processing $a"
# Do something with $a ...
systemd-notify --status="Waiting for data..."
done