{ ... }:
{
  text = ''
    # Burn specified iso file to DVD.
    # Usage: dvd_burn_iso <FILE.iso>
    function dvd_burn_iso() {
      local iso="''${1}"
      if [[ "''${iso}" = "" ]]; then
        help dvd_burn_iso
        return 2
      fi

      growisofs -dvd-compat -speed=8 -use-the-force-luke=tty -Z /dev/sr0="''${iso}"
    }

    # Burn specified iso file to CD.
    # Usage: cd_burn_iso <FILE.iso>
    function cd_burn_iso() {
      local iso="''${1}"
      if [[ "''${iso}" = "" ]]; then
        help cd_burn_iso
        return 2
      fi

      wodim speed=8 -tao dev=/dev/sr0 "''${iso}"
    }

    # Burn specified audio files to CD.
    # Usage: cd_burn_audio <FILES.wav>
    function cd_burn_audio() {
      if [[ "''${*}" = "" ]]; then
        help cd_burn_audio
        return 2
      fi

      cdrecord -v dev=/dev/sr0 speed=8 -audio -pad "''${*}"
    }

    # Spawn Nix shell with required tools.
    function dvd_shell() {
      SHELL_NAME="dvd" tmpshell dvdplusrwtools cdrkit
    }
  '';
}