Get users home directory when they run a script as root

Question

I have a sh script that needs to be run as root, however it is run by the end user using sudo. How can I get the users home directory when ~/ points to /root when running with s

Answer 1

$ sudo env |grep USER
USER=root
USERNAME=root
SUDO_USER=glglgl

So you can access $SUDO_USER and ask the system for his homedir with getent passwd $SUDO_USER | cut -d: -f6.