Tmux helper to list tmux sessions, attach to an existing session, or create a brand new one!

tmux-helper

function tm() {
  if [ -n "$1" ]; then
    tmux attach -t $1 2>/dev/null || tmux new -s $1
  else
    tmux list-sessions 2> >(grep -q 'failed')
    if [ "$?" -eq 1 ]; then
      echo "No available tmux sessions. Please create one."
    fi
  fi
}