zsh function to restart Rails server (only support nginx server with passenger or unicorn_rails)

.zshrc

rtouch() {
  emulate -L zsh
  if [[ -d tmp ]]; then
    if which passenger 2>&1 >/dev/null; then
      touch tmp/restart.txt && echo 'file touched.'
    elif which unicorn_rails 2>&1 >/dev/null; then
      if [[ -r tmp/pids/unicorn.pid && -n $(ps h -p `cat tmp/pids/unicorn.pid` | tr -d ' ') ]]; then
        kill -USR2 $(cat tmp/pids/unicorn.pid) && echo "process killed."
      elif [[ -f config/unicorn.rb ]] && [[ -n $RAILS_ENV ]]; then
        bundle exec unicorn_rails -D -E $RAILS_ENV -c config/unicorn.rb && echo "process started."
      else
        echo "ERROR: no config for unicorn_rails."
      fi
    else
      echo 'ERROR: no "passenger" or "unicorn_rails" available.'
    fi
  else
    echo 'ERROR: "tmp" directory not found.'
  fi
}