Your change is superficial : you also have to rename your user folder. While it is pretty easy to change your computer name on OS X, OS X does not natively handle changing your username, the solution is pretty hackish. In addition to what you have done, you have to create a new user with admin right (name it whateever you want as it would be a temporary account), login in this user, then change the name of your other admin folder (the old one). The problem is that some software rely on absolute path and they won't now where are all the files they created once you have rename your user folder. For instance, I lost all of my
vmdk files as well as my calibre library and was worried at first when I rebooted (I thought I lost everything the first time OS X rebooted, i.e., the time OS X makes the correspondence between the folder of my admin user and the admin account himself).
To answer your question : If you do not want to go through this, you could, in your
\u and just type your username in plain text, make this hack an exception (only for the local host as it won't change) so that when you connect to an other computer (with ssh for instance) the correct username will be displayed.
Edit thanks to RobertL's remark: What I did :
1) RobertL's step 2
2) Rename my user folder within finder (in finder menu bar : Goto--> computer --> macintosh HD (or the name of your drive) --> users --> right click on my user --> read informations (or cmd + i) --> rename in the box at the bottom.