
To kill a frozen OpenSSH session, type “⏎ ~ .” – aka Enter, Tilde, Period - i336_
http://blog.infertux.com/2012/12/20/properly-close-a-frozen-ssh-session/
======
i336_
...Or in British English, "Full-Stop."

Type "⏎ ~ ?" for a tiny options menu!

Credit where credit is most definitely due:
[https://www.reddit.com/r/linux/comments/4hlsmn/til_how_to_pr...](https://www.reddit.com/r/linux/comments/4hlsmn/til_how_to_properly_close_a_frozen_ssh_session/)

As one of the commenters in that thread noted, "Open command line" in the
aforementioned options menu lets you manipulate the port forwarding table in
an open session; type 'h' for further help.

And as another commenter said, I guess I should have properly gone through the
manpage for SSH at some point (along with many other manpages)...

I'm very interested to know where this feature does/does not work on the
various variants of UNIX and BSD that are out there. I expect this is a
standard OpenSSH feature, but when was it introduced, and how widely is it
supported?

\---

Also, as a semi-rant aside: the usage of the Enter key is an incredibly,
incredibly poor choice - what about the scenario where the connection has died
badly enough that update packets are being dropped, but your keystrokes are
getting through, and the remote system gets into a state where you would NOT
want to send a carriage return?

I've had VNC freeze up on me once or twice where I reconnect and find that my
typing input got through, but that the display updates just couldn't make it
back. Granted, VNC is a bit heftier than SSH, but if in certain situations I
don't think I'd feel too bad about chickening out and resorting to `kill` (or
^B X, as the author writes).

Also, I don't think I need to add "(2012)" to the end of this.

~~~
JdeBP
It dates back to the rlogin command from 4.2BSD in 1983.

Technically, the return key isn't part of the sequence. An _escape sequence_
in rlogin is defined as a line where a tilde, or (more properly) the _escape
character_ (since it can be changed with a command-line option), is the first
character that is typed at the start of a line.

* [https://docs.oracle.com/cd/E19683-01/816-0210/6m6nb7mjg/inde...](https://docs.oracle.com/cd/E19683-01/816-0210/6m6nb7mjg/index.html)

* [http://www.gnu.org/software/inetutils/manual/html_node/rlogi...](http://www.gnu.org/software/inetutils/manual/html_node/rlogin-invocation.html)

rlogin wasn't the only command where a line starting with an _escape
character_ was special. When Berkeley Mail was in compose mode, one could do
various things with such lines.

* [https://docs.freebsd.org/44doc/usd/07.mail/paper.pdf](https://docs.freebsd.org/44doc/usd/07.mail/paper.pdf)

