by NIX CRAFT on NOVEMBER 12, 2007 · 22 COMMENTS· LAST UPDATED JANUARY 6, 2008 in CENTOS, DEBIAN LINUX, FREEBSD
http://www.cyberciti.biz/tips/shell-root-user-check-script.html
Sometime it is necessary to find out if a shell script is being run as root user or not.
When user account created a user ID is assigned to each user. BASH shell stores the user ID in $UID variable. Your effective user ID is stored in $EUID variable. You can