Automatically Attach tmux in SSH Session

Posted on 2015-05-09

I frequently work in ssh sessions and have found terminal multiplexers like tmux to be invaluable. The problem I was constantly facing was having to re-attach or create a new session each time I would ssh into a machine. Sometimes I would accidentally create a new session when one already existed and would then have to find where I had been working previously.

After searching around, I found a nice way to automatically create a session each time I ssh into a machine, or re-attach if it already exists.

if [[ "$TMUX" == "" ]] &&
        [[ "$SSH_CONNECTION" != "" ]]; then
    # Attempt to discover a detached session and attach
    # it, else create a new session
    WHOAMI=$(whoami)
    if tmux has-session -t $WHOAMI 2>/dev/null; then
    tmux -2 attach-session -t $WHOAMI
    else
        tmux -2 new-session -s $WHOAMI
    fi
fi

I first check to be sure I'm not in a screen session and also that I'm using ssh and not local to my machine. After that, it's a simple check to see if a session exists. If so, re-attach it, otherwise create a new one. This can be simple added to the bottom of your ~/.bashrc file. Now every time I ssh in to any machine, my previous session is sitting there waiting for me.

Tags: automation bash