Start tmux automatically on zsh

start-tmux-automatically-on-zsh.zsh

# Let's kick things off by checking if we're already in a tmux session
if [[ ! -n $TMUX  ]]; then
  # Gather the mystical details of existing tmux sessions
  session_details="$(tmux list-sessions)"

  # Uncomment this block to create a new session if no sessions exist
  # if [[ -z "$session_details" ]]; then
  #   tmux new-session  # Bring a new session into existence!
  # fi

  # Presenting the user with choices to manage their tmux experience:
  #   - Attach to an existing session if there are any
  #   - Create a new tmux session for fresh adventures
  #   - Or, take the plunge and start without tmux altogether!
  create_new_session="Create new tmux session"
  start_without_tmux="Start without tmux"
  choices="${create_new_session}\n${start_without_tmux}"  # Initialize the choice menu
  
  # If there are existing sessions, add them to the choices
  if [[ ! -z "$session_details" ]]; then
    choices="$session_details\n$choices"  # Add existing sessions to the mix
  fi
  
  # Use fzf to present the choices in a friendly way and get the user's selection
  choice="$(echo -e $choices | fzf | cut -d: -f1)"

  # Fetch the current session IDs for validation
  session_ids="$(tmux list-sessions -F '#S')"
  
  # Check if the choice is valid: alphanumeric and exists in session IDs
  if expr "$choice" : "^[a-zA-Z0-9]*$" >&/dev/null && echo "$session_ids" | grep -q -w "$choice"; then
    # If valid, let's attach to the chosen session like a pro
    tmux attach-session -t "$choice"
  elif [[ "$choice" = "${create_new_session}" ]]; then
    # Time to create a brand new session—let the magic happen!
    tmux new-session
  elif [[ "$choice" = "${start_without_tmux}" ]]; then
    # Starting without tmux? You do you! Nothing to do here.
    :
  fi
fi

You need to install fzf first: FZF