exit out of all SSH connections in one command and close PuTTY

Question

Is there a way to back out of all SSH connections and close PuTTY in "one shot"? I work in Windows 7 and use PuTTY to SSH to various Linux hosts.

An example of the way I find myself working:

SSH to host1 with PuTTY...
banjer@host1:~> #...doin some work...ooh! need to go check something on host8...
banjer@host1:~> ssh host8
banjer@host8:~> #...doin some work...OK time for lunch. lets close putty...
banjer@host8:~> exit
banjer@host1:~> exit
Putty closes.

Per above, any way to get from host8 to closing PuTTY in one shot? Sometimes I find myself up to 5 or 10 hosts deep. I realize I can click the X to close the PuTTY window, but I like to make sure my SSH connections get closed properly by using the exit command. I also realize I'm asking for tips on how to increase laziness. I'll just write it off as "how can I be more efficient".

Solution 1

Try using the ssh connection termination escape sequence.

In the ssh session, enter ~. (tilde dot). You won't see the characters when you type them, but the session will terminate immediately.

$ ~.
$ Connection to me.myhost.com closed.  

From man 1 ssh

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 for SSH protocol
         version 2 and if the peer supports 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 remote port-forwardings using 
         -KR[bind_address:]port.  !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 for SSH protocol 
         version 2 and if the peer supports it).

Solution 2

Just press Ctrl + D to exit and it will log you out. Hold Ctrl and press D repeatedly to log you out of multiple windows, tabs, or levels until the window disappears.

Solution 3

Simply close PuTTY. (Alt+F4 by default IIRC.)

Solution 4

If you don't mind doing a little scripting you can do this.

Script: myssh.sh

#!/bin/bash
ssh $1
if [ $? -eq 5 ]; then
 exit 5
fi

Call via the dot command:

$ . myssh [email protected]

If you want to exit one level:

$ exit

If you want to exit all:

$ exit 5

Solution 5

Or you could use exec to replace your shell process with ssh when jumping to another host:

SSH to host1 with PuTTY...
banjer@host1:~> #...doin some work...ooh! need to go check something on host8...
banjer@host1:~> exec ssh host8
banjer@host8:~> #...doin some work...OK time for lunch. lets close putty...
banjer@host8:~> exit
Putty closes.

5 levels deep is not pretty, since the traffic will pass through all the other servers. Because of that I don't recommend just killing PuTTY or ssh (~.), since (depending on what you do) this could result in orphaned processes on the servers.

Better to try and be less "lazy". Right-click on puttys title bar makes opening a new session quick. If you have a "default" server and accept 1 jump from that, the "Duplicate Session" feature is very useful. Especially when using pubkey authentication.

View more solutions

Comments

[devarni]

Pretty cool! Any way to put ~. into an alias or function? Just to give it an easy to remember name like exitall. Now I'm asking for way too much :). I tried a few things in ~/.bashrc but get -bash: ~.: command not found. I suppose bash sees it as a string and not an escape sequence coming directly from the keyboard.

[devarni]

I like the ctrl+d solution as well, but this answers my question more directly. Thanks all.

[devarni]

@Gilles gotcha, makes sense.

[Simon Gates]

Sadly, this doesn't work universally. Any session running an editor or other full screen tool is likely to ignore EOT. And even bash will ignore it in the middle of a command line. Try it out yourself: type a single letter and try Ctrl-D.

[Simon Gates]

And there's no guarantee that PuTTY also does this. The CLI ssh client needs this technique because it's CLI. PuTTY is a GUI application and there are far more user-friendly ways to do this stuff on a GUI.

[clerksx]

function is not POSIX -- just remove the keyword, and you need to quote $@ properly, or your arguments will be passed after word splitting (bad).

[user3731606]

Of course, you would have copy it to every computer that you may ever ssh from. Also, wouldn't it be easier to just define a shell function called ssh? That would avoid the preceeding period, etc.

[Joe]

It safely exits. It is a shell shortcut that is the same as typing 'exit' and pressing enter.

[velis]

Actually mine (windows git bash & ubuntu bash) issue a logout.

[Joe]

yes, I believe exit also calls logout as ssh connections tend not to be login sessions.

[G-Man Says 'Reinstate Monica']

I believe that you didn't read the question correctly. OP does ssh host1, and then, from host1, does ssh host8. At that point a logout would do the same thing as the exit command they already know — exit out of host8 and put them back into host1.

[Richard]

Ok, I see, my bad.

[mwfearnley]

Interesting. I've never heard of these ssh features until today. PuTTY doesn't seem to have them though.