A script I wrote to preview a build directory (in my case Hugo's `public` folder, but adjust to taste).

preview.sh

#!/bin/sh

port=${1-1919}

# 1. Navigate to the built folder & start a server in it
cd public
python -m SimpleHTTPServer "$port" &
server_pid=$!

# 2. Trap any killing of this process so that we kill the backgrounded server
function kill_server {
  kill $server_pid
}
trap kill_server EXIT

# 3. Wait a tiny bit for the server to boot, then open a browser window
sleep 0.1
open "http://localhost:$port"
wait $server_pid