sudo

Introduction
allows normal users to run command as root

Install sudo
apt-get install sudo

Configuration
Edit /etc/sudoers and enter these 2 lines:
uname    host=(runas) cmd
alan     pc1,pc2=(root,daemon) /bin/ls,/bin/cp,/usr/bin/whoami

Using sudo
sudo whoami
sudo -u david whoami

Get full sessions as root
sudo su –

Logging
/var/log/auth.log