3 ms·

To kill a frozen OpenSSH session, type “⏎ ~ .” – aka Enter, Tilde, Period

2 points by i336_ 11y ago

i336_ 11y ago
...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_properly_close_a_frozen_ssh_session/ https://www.reddit.com/r/linux/comments/4hlsmn/til_how_to_pr... 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 11y ago
  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/index.html https://docs.oracle.com/cd/E19683-01/816-0210/6m6nb7mjg/inde... * http://www.gnu.org/software/inetutils/manual/html_node/rlogin-invocation.html http://www.gnu.org/software/inetutils/manual/html_node/rlogi... 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

2 points by i336_ 11y ago

i336_ 11y ago

...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_properly_close_a_frozen_ssh_session/ https://www.reddit.com/r/linux/comments/4hlsmn/til_how_to_pr... 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 11y ago
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/index.html https://docs.oracle.com/cd/E19683-01/816-0210/6m6nb7mjg/inde... * http://www.gnu.org/software/inetutils/manual/html_node/rlogin-invocation.html http://www.gnu.org/software/inetutils/manual/html_node/rlogi... 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