Is it a bad idea to do usermod -l login-name old-name to change my username while leaving my home directory name intact? A few years ago my university changed my username, but since it didn't affect anything, I did not change my local username. Now in order to use our centralized printers, the local username must match the university username (or so they claim). The reason I don't want to change my home directory is twofold. I think there are a number of scripts that have my username hardcoded into them. I think a change in my home directory name might throw my backup and revision control systems into a state of chaos.
Changing username but not home directory
users
There are no purely technical reasons. It might create some confusion in cases where the USER environment variable is consulted while either $HOME, getpwuid(getuid()) or something similar should have been used.By the way you can even have multiple usernames assigned to the same UID - locally this is achieved by multiplicating the appropriate lines in /etc/passwd, /etc/shadow and updating /etc/group accordingly. The ownership of files doesn't change (usually the first one found in /etc/passwd for the corresponding UID is displayed) and you can use any of the usernames you decide.