221

I’m connecting to a server via SSH to send a message to a socket server using a command like:

ssh 181.169.1.2 -p 5566

After the connection is established and I write the message and send it I can’t exit the text mode. I’m only allowed to enter more text and that’s it.

Is there a command or a key combination that allows me to return to command mode?

120

How do I exit an SSH connection?

Two ways:

  • closing the shell session, e.g. with exit followed by Enter, or Ctrl-d usually allows you to exit the ssh session normally,
  • in the case where you have a bad connection and the shell is unresponsive, hit the Enter key, then type ~. and ssh should immediately close and return you to your command prompt.

The first option should be intuitive, but how do we know the latter option?

We could learn this information from a careful reading of the man page.

$ man ssh

gives us the SSH documentation, which has the following section on escape characters:

ESCAPE CHARACTERS
     When a pseudo-terminal has been requested, ssh supports a number of
     functions through the use of an escape character.

     A single tilde character can be sent as ~~ or by following the tilde by
     a character other than those described below.  The escape character
     must always follow a newline to be interpreted as special.  The escape
     character can be changed in configuration files using the EscapeChar
     configuration directive or on the command line by the -e option.

     The supported escapes (assuming the default ‘~’) are:

     ~.      Disconnect.

     ~^Z     Background ssh.

     ~#      List forwarded connections.

     ~&      Background ssh at logout when waiting for forwarded connection
             / X11 sessions to terminate.

     ~?      Display a list of escape characters.

     ~B      Send a BREAK to the remote system (only useful if the peer sup‐
             ports it).

     ~C      Open command line.  Currently this allows the addition of port
             forwardings using the -L, -R and -D options (see above).  It
             also allows the cancellation of existing port-forwardings with
             -KL[bind_address:]port for local, -KR[bind_address:]port for
             remote and -KD[bind_address:]port for dynamic port-forwardings.
             !command allows the user to execute a local command if the
             PermitLocalCommand option is enabled in ssh_config(5).  Basic
             help is available, using the -h option.

     ~R      Request rekeying of the connection (only useful if the peer
             supports it).

     ~V      Decrease the verbosity (LogLevel) when errors are being written
             to stderr.

     ~v      Increase the verbosity (LogLevel) when errors are being written
             to stderr.
  • I don't find the "how do we know this" section particularly helpful, because to me it implies that there is some sort of obvious-to-find solution, when I don't find it particularly intuitive that I would "man ssh" to find how to disconnect. How would I have found "exit", for example? I do agree it's good to reaffirm checking the man pages when you can. – Alexander Pritchard Oct 11 '17 at 15:49
  • @AlexanderPritchard I have updated my answer to more carefully explain what we're doing here. If you find the man page difficult to understand, file an issue with the maintainer, or even better, submit a pull request with an (unqualifyingly good) improvement. – Aaron Hall Oct 11 '17 at 17:01
  • 1
    That sounds good in theory, but in practice, many people struggle to figure out how to navigate these commands because even knowing how to look for the information you want assumes context people do not have. Filing an issue with maintainers and submitting pull requests with improvements goes even further beyond this. I do not argue that man pages are useful, but if they were as definitively useful as some make them seem, I wouldn't be using Stack Exchange. I want to be clear I think your answer is fine, and that people should check the man pages, but they are not all-encompassingly useful. – Alexander Pritchard Oct 12 '17 at 17:54
  • 4
    "if they were as definitively useful as some make them seem, I wouldn't be using Stack Exchange." I agree, and that's why I try to write good answers. Citing and quoting reference sources is not to make anyone feel dumb or bad for not having already read from that source, it is done to provide further evidence for what would otherwise be a perhaps demonstrable assertion of fact, as well as inform the user where more relevant information may be stored. You want to know that you're doing semantically the correct thing, as well as knowing that it works. – Aaron Hall Oct 12 '17 at 18:20
270

Short answer: Type exit

If that doesn't work, however...

SSH Escape Character and Disconnect Sequence

Most SSH implementations implement an escape character for interactive sessions, similar to telnet's Ctrl-] combination. The default SSH escape character is ~, entered at the beginning of a line.

If you want to terminate an interactive OpenSSH session which is stuck and cannot be exited by entering exit or CtrlD into a shell on the remote side, you can enter ~ followed by a dot .. To be sure to enter the escape character at the beginning of an input line, you should press Enter first. So the following sequence will in most cases terminate an SSH session:

Enter~.

Other Escape Sequences

OpenSSH, for example, offers other escape sequences besides ~.. Entering ~? during a session should give you a list. Some examples:

  • ~ followed Ctrl-Z suspends the session,
  • ~& puts it directly into background,
  • ~# gives a list of forwarded connections in this session.
  • If you want to simply enter a tilde at the beginning of a line, you have to double it: ~~.

The escape character can be changed using the command line option -e. If you set the special value -e none, escaping is disabled and the session is fully transparent.

See also the OpenBSD man page on ssh (which is referenced from www.openssh.org) under the -e command line option

  • 2
    Why make it simple when you can have it uselessly complicated? – MariusMatutiae Jun 6 '14 at 12:14
  • 7
    @MariusMatutiae The OP asked for a case where there was no remote shell to enter exit or Ctrl-D, but just a listening process. I clearly stated that my solution is suited for a session which is stuck and cannot be exited. I tried to clarify this more, hope it is easier to see now. – Dubu Jun 10 '14 at 9:47
  • 5
    I was sceptical, but ~. without spaces was exactly what I needed, thanks! :) – Jamey Jun 25 '14 at 14:38
  • 2
    In swiss german keyboard layout, tilde is generated by pressing AltGr+^ (plus it's a blocking key). Because of this, it seems that the escape sequence doesn't work. Does anyone know how to type the default escape in swiss german? – Daniel Alder Dec 1 '14 at 12:14
  • 4
    @Dobu Found the reason why it didn't work before. If you already typed ~ in the same line (which easily happens if you are testing), the following ~. sequences are ignored. Had to press return first... – Daniel Alder May 20 '15 at 13:16
33

Do you want to exit the SSH shell?

You can type exit and hit Enter, or use Ctrl+D

  • 1
    "exit" helped me as ctrl+d not worked in VNC viewer...thanks – raj gupta Jun 10 '13 at 7:57
  • 1
    This doesn't work in cases where the machine freezed or disappeared or the application doesn't respond to any input – Daniel Alder May 20 '15 at 11:36
11

Just type exit or logout (then hit Enter of course) both will work.

4

You can write logout in the console line (and hit Enter of course).

4

These are the supported characters which provide various options with which you can play around with ssh.

Supported escape sequences:

 ~.  - terminate session

 ~B  - send a BREAK to the remote system

 ~R  - Request rekey (SSH protocol 2 only)

 ~#  - list forwarded connections

 ~?  - this message

 ~~  - send the escape character by typing it twice

(Note that escapes are recognized only immediately after a newline.) You can close the list of Escape sequences by hitting Enter.

2

MacOS: when ssh hangs use following sequence:

ENTER 
SHIFT+`
.

where: shift+` produces ~ (tilde character)

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.