Use with --enable to set the site in Emergency Off-line Mode.

Use with --disable to take the site out of the Emergency Off-line Mode.

Unlike the Emergency Off-Line button in Admin Tools' Control Panel, this command cannot know your IP address; there is no web request for it to read it from. It will therefore block everyone, including you, until you run it again with --disable. Use --exempt-ip with your own IP address, e.g. admintools:offline --enable --exempt-ip=203.0.113.14, to keep a way into your site.