systemd-activate — Test socket activation of daemons
/usr/lib/systemd/systemd-activate [OPTIONS...] daemon [OPTIONS...]
systemd-activate can be used to launch a socket activated daemon from the command-line for testing purposes. It can also be used to launch single instances of the daemon per connection (inetd-style).
The daemon to launch and its options should be specifed after options intended for systemd-activate.
If the -a option is given, file descriptor
of the connection will be used as the standard input and output of
the launched process. Otherwise, standard input and output will be
inherited, and sockets will be passed through file descriptors 3
and higher. Sockets passed through $LISTEN_FDS
to systemd-activate will be passed through to
the dameon, in the original positions. Other sockets specified
with --listen will use consecutive descriptors.
--help, -hPrints a short help text and exits.
--versionPrints a short version string and exits.
-l, --listen=addressListen on this address.
Takes a string like 2000 or
127.0.0.1:2001.
-a, --acceptLaunch a separate instance of daemon per connection and pass the connection socket as standard input and standard output.
$LISTEN_FDS, $LISTEN_PIDSee sd_listen_fds(3).
$SYSTEMD_LOG_TARGET, $SYSTEMD_LOG_LEVEL, $SYSTEMD_LOG_COLOR, $SYSTEMD_LOG_LOCATIONSame as in systemd(1).
$ /usr/lib/systemd/systemd-activate -l 19531 /usr/lib/systemd/systemd-journal-gatewayd
This runs a socket activated instance of systemd-journal-gatewayd(8).