if (( SHLVL == 1 )); then
  if [ -x /usr/bin/clear_console ]; then
    /usr/bin/clear_console -q
  elif [ -x /usr/bin/clear ]; then
    /usr/bin/clear
  elif [ -x /usr/bin/tput ]; then
    /usr/bin/tput clear
  else
    echo -ne "\E[2J"
  fi
fi