Ssh – How to configure SSH with a RemoteCommand only for interactive sessions (i.e. without command, or not sftp)

sftpsshssh-config

Currently I use Fish as my main shell on local and remote hosts.

I connect to remote hosts via ssh and sftp. I wanted to open or reuse a remote tmux whenever I connect, automatically, by default; so I added this to my ~/.ssh/config:

Host example.com
RemoteCommand tmux a; or tmux
RequestTTY yes

The problem is that now I cannot connect through sftp, nor can I run a direct command from my local CLI:

➤ ssh example.com ping localhost
Cannot execute command-line and remote command.

➤ sftp example.com
Cannot execute command-line and remote command.
Connection closed

So, my question is: How can I define a default command to be executed when opening a new interactive SSH session, but make it overridable?

Best Answer

Option 1 )

You can the option Match ( see man ssh_config )

Match Host example.com exec "test $_ = /usr/bin/ssh"
     RemoteCommand tmux a; or tmux
     RequestTTY yes

This will only differentiate difference between ssh & sftp

Option 2

You create some placeholder config for your diffe command , example :

Host tmux.example.com
  HostName example.com
  HostKeyAlias example.com
  RemoteCommand tmux a; or tmux
  RequestTTY yes

And after you can still use example.com for you sftp / ping usage .

Related Solutions

SSH – Using LocalCommand on Exit

It's not specified in the question if you want this executed on the local or remote machine. It's also not specified which shell is present on either machine, so I'm assuming bash for both.

If you want to execute it on the remote machine, look at ~/.bash_logout, which is executed when a login shell logs out gracefully. From man bash:

When a login shell exits, bash reads and executes commands from the file ~/.bash_logout, if it exists.

You can do a test in ~/.bash_logout to check if the shell being logged out of is an SSH session, something like the following should work:

if [[ $SSH_CLIENT || $SSH_CONNECTION || $SSH_TTY ]]; then
    # commands go here
fi

If you want to execute it on the local machine, create a function wrapper around ssh. Something like the following should work:

ssh() {
    if command ssh "$@"; then
        # commands go here
    fi
}

That may be too simple for your needs, but you get the idea.

Ssh – execute commands from a midnight commander ssh connection

No, it's not possible.

the fact that the link uses a remote shell is abstracted away by the VFS layer, so: no. http://gnome-apps.13852.n7.nabble.com/Execute-command-on-a-shell-link-td63584.html

Best Answer

Related Solutions

SSH – Using LocalCommand on Exit

Ssh – execute commands from a midnight commander ssh connection

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