[xubuntu-users] Detecting login name after su

[Peter Flynn]

On 10/04/2013 08:34 AM, Jan Henke wrote:
> Hi,
> 
> the command 'w' lists all currently logged in users together with the
> source of the login. You can parse that output to look for you local
> machine (IP address or reverse DNS name), then you have the user name.

Hah! That's it, thanks...I had completely forgotten about it.

$ ssh xyz at foo.bar.com
xyz at foo.bar.com's password:
Last login: Thu Oct  3 23:56:16 2013 from blort.bar.com
$ sudo su -
[sudo] password for xyz:
# w -u | grep 'w -u$' | awk '{print $1}'
xyz
#

gives the username you originally logged in as (here 'xyz').

///Peter