PS1 설정에 사용할것
from https://unix.stackexchange.com/questions/14345/how-do-i-tell-im-running-in-a-chroot

if [ "$(stat -c %d:%i /)" != "$(stat -c %d:%i /proc/1/root/.)" ]; then
  echo "We are chrooted!"
else
  echo "Business as usual"
fi