Simple Bash Script to Create a New Session

tmux-new.sh

#!/bin/bash
# USAGE: ./tmux-new.sh SESSION_NAME
#
# Credit to Keon Woortman
# URL: https://koenwoortman.com/tmux-sessions-should-be-nested-with-care-unset-tmux-to-force/

session_name="$1"

# 1. First you check if a tmux session exists with a given name.
tmux has-session -t=$session_name 2> /dev/null

# 2. Create the session if it doesn't exists.
if [[ $? -ne 0 ]]; then
  TMUX='' tmux new-session -d -s "$session_name"
fi

# 3. Attach if outside of tmux, switch if you're in tmux.
if [[ -z "$TMUX" ]]; then
  tmux attach -t "$session_name"
else
  tmux switch-client -t "$session_name"
fi