Changelog for a recent release of SecureShell for Chrome
included a mention of “Support for iTerm2 OSC-9 growl notifications”. This is displayed in terminal when you’re SSHing into a machine, and this entry piqued my interest.

Turns out it’s from hterm’s changelog. And turns out hterm has a nice list of supported control sequences.

OSC are “operating system command” control sequences and there’s a few of them supported by hterm / SecureShell. I find a few super interesting (\033 being ESC in the doc linked above):

• 0: set window title: echo -e "\033]0;This is the window title\a"
• 9: show system notification (iTerm2 variant): echo -e "\033]9;This is the notification text\a"
• 777: show system notification (rxvt-unicode / urxvt variant): echo -e "\033]777;notify;This is the notification title;This is the notification text\a"
• 52: clipboard operation; hterm only supports c for copy: echo -e "\033]52;c;$(base64 <<< hello)\a"