how to test if user is root or not in a shell script?

dr_zayus69 · 08-16-2005, 03:43 PM

hi im making a script that will excecute some commands but you need to be root to do so but i don't know how to check to see if the current user is root or not - how would i do so? Thanks for any replies in advance.

edit: i just realized that i could put the output of whoami to a variable and test against that. but is there another way to do so to increase teh portability of the script? Were does whoami get it from?

mai1man · 08-16-2005, 03:46 PM

$UID

root's UID=0

dr_zayus69 · 08-16-2005, 03:58 PM

thanks, that seems more concise then capturing the output of whoami.

heema · 08-17-2005, 03:00 AM

Code:

# Run as root

ROOT_UID=0     # Only users with $UID 0 have root privileges.
E_NOTROOT=67   # Non-root exit error.

if [ "$UID" -ne "$ROOT_UID" ]
then
 echo "Must be root to run this script , type su to change to root."
 exit $E_NOTROOT
fi