Once sudo su'd to root, is there a command to see my username?
The shell's parent process is
su -, and the parent of that is the
sudo su -. So you need to find out the user running
sudo su -'s parent process by searching back in two steps with
ps -o user= $(ps -o ppid= $(ps -o ppid= $PPID))
But you shouldn't be doing
sudo su - if your version of sudo is not too old to have
sudo -i. Sudo sets the environment variable
SUDO_USER to the name of the user who ran sudo. You won't see it with
sudo su - because
su - scrubs the environment.
$ sudo -i # echo $SUDO_USER gilles
whoami it will return you something like that:
gladimdim tty2 2011-01-27 23:54 (:0)
In bold "gladimdim" is the user which was initially logged to system.