Ubuntu Forums - View Single Post - [all variants] Difference between sudo su and sudo -s

unutbu

I did the following experiment:

Code:

applic@ion:~% sudo su
[sudo] password for applic:
root@ion:/home/applic# env > /tmp/sudo_su_env
root@ion:/home/applic# exit
exit
applic@ion:~% sudo -s
applic .bashrc read...
root@ion:~% env >/tmp/sudo_s

Here are the differences I found:

"sudo -s"
HOME=/home/applic
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/X11R6/bin
reads $USER's ~/.bashrc
"sudo su"
HOME=/root
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
reads /etc/environment
reads /root/.bashrc

Notice the difference in $HOME. Being root and having $HOME set to the normal user's home can cause problems. For example, if you run a graphical app, the normal user's ~/.Xauthority can get overwritten by root. This causes the normal user problems later on such as not being able to run certain graphical apps through cron.

Here is a summary:

Code:

				                     corrupted by user's 
		HOME=/root	uses root's PATH     env vars
sudo -i		Y		Y[2]                 N
sudo -s		N		Y[2]                 Y
sudo bash	N		Y[2]                 Y
sudo su		Y		N[1]                 Y


[1] PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
    probably set by /etc/environment
[2] PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/X11R6/bin

The bottom line, is "sudo -i" is the proper command to run when you want a root shell that is untainted by the user's environment.

November 16th, 2008	#4
unutbu Extra Roomy Joe Join Date: Mar 2008 Beans: 4,715 Ubuntu 9.10 Karmic Koala	Re: Difference between sudo su and sudo -s I did the following experiment: Code: applic@ion:~% sudo su [sudo] password for applic: root@ion:/home/applic# env > /tmp/sudo_su_env root@ion:/home/applic# exit exit applic@ion:~% sudo -s applic .bashrc read... root@ion:~% env >/tmp/sudo_s Here are the differences I found: "sudo -s" HOME=/home/applic PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/X11R6/bin reads $USER's ~/.bashrc "sudo su" HOME=/root PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games reads /etc/environment reads /root/.bashrc Notice the difference in $HOME. Being root and having $HOME set to the normal user's home can cause problems. For example, if you run a graphical app, the normal user's ~/.Xauthority can get overwritten by root. This causes the normal user problems later on such as not being able to run certain graphical apps through cron. Here is a summary: Code: corrupted by user's HOME=/root uses root's PATH env vars sudo -i Y Y[2] N sudo -s N Y[2] Y sudo bash N Y[2] Y sudo su Y N[1] Y [1] PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games probably set by /etc/environment [2] PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/X11R6/bin The bottom line, is "sudo -i" is the proper command to run when you want a root shell that is untainted by the user's environment.