How to remove 'connection to xx.xxx.xx.xxx closed' message?

Question

#!/bin/bash

ssh -t $SSH "
    some
    commands
"

Where is the 'connection to xx.xxx.xx.xxx closed' message coming from? I can't stop it even with result=ssh ...

Answer 1

That is coming from SSH. You see it because you gave the -t switch, which forces SSH to allocate a pseudo-terminal for the connection. Traditionally, SSH displays that message to make it clear that you are no longer interacting with the shell on the remote host, which is normally only a question when SSH has a pseudo-terminal allocated.

Answer 2

if you add -o LogLevel=QUIET to the SSH command line, that message should disappear:

ssh -o LogLevel=QUIET -t $SSH "
      some 
      commands
"

You can also add it to the ~/.ssh/config file as a line saying LogLevel QUIET

Answer 3

As Fran mentioned, this is coming about because of the -t switch. You can hide the message by appending:

 2> /dev/null

Your code would look like this:

#!/bin/bash

ssh -t $SSH "
    some
    commands
" 2> /dev/null

This redirects STDERR to /dev/null. Keep in mind all error messages that may be raised will also be redirected to /dev/null and so will be hidden from view.

Answer 4

Could not comment on Fran's answer which is the correct one.

Just wanted to add that your code fragment looks like a script, which means you are likely calling remote stuff which is not depending on an interactive screen (unlike for example mc or top which make little sense without a keyboard and a screen - you will therefore not use these programs in scripts).

So you are better off explicitly without a terminal. That means replace the -t flag with the -T flag. Longer syntax which I prefer in scripts to make them more self evident and readable would be: -o 'RequestTTY no' vs. -o 'RequestTTY yes'.

And while at that, forget the -o LogLevel=QUIET solution suggested by Leo - it hides error messages too. If your script faces some unfavourable circumstances, you will not understand what went wrong. In scripts you probably want to use -o LogLevel=ERROR - this suppresses the remote machine's banner if it has one, but lets error messages through.