Modifying Username
I modified a users name on my system. From ABCLast, to ALast (used as an example).
I modified the username, then the group name of the user (to align with the new name), and then I
moved the users home directory from /home/ABCLast, to /home/ALast. Then using vipw, edited the home directory to use /home/ALast.
When I got finished editing the passwd file, I got the following message:
You have modified /etc/passwd. You may need to modify /etc/shadow for consistency.
I don’t know what to do here. Need some guidance please.
lastly, did I miss anything here? Any other steps I need to do to get this user squared away due to the name change?
Thanks,
Jay
7 thoughts on - Modifying Username
Run “vipw -s” and make the same change to that file’s record for ABCLast.
In /etc/passwd the directory was shown in plain text. So I just moved over in the line and changed /home/ABCLast to /home/ALast. Saved file, and exited.
I don’t see a directory name in /etc/shadow using ‘vipw -s’
Jay
The /etc/shadow file doesn’t have the user directory information, rather the username and the password (and some other bits – man shadow for the details). With the /etc/passwd and /etc/shadow out of sync – having different versions of the username – I suspect that the user can’t log in. You should also fix the shadow group file
(gshadow). Look at the man page for vipw for the command for doing that.
All files seem to have the correct updated username, and the user can login.
Jay
No, there’s no directory in /etc/shadow, but the username (the first field) will need to be changed to match with the one in /etc/passwd. Apologies if you know this: /etc/passwd contains account information and is world readable because lots of programs need the information in it, the encrypted password use to be in that file (hence the name) but it too was visible and hence available for cracking; /etc/shadow is not world readable and holds all the “secret” password info; the only thing linking the two databases is the username, hence that has to match in the two files.
P.
Whenever you are attempting to edit UNIX user related files manually, keep in mind that information in the following files should be changed
(not necessarily in all, depending on what you change):
/etc/passwd
/etc/shadow
/etc/group
/etc/gshadow
There are also “previous versions” of each of these files which have the same names appended by hyphen (“minus”).
Also, keep in mind that permissions for all of these files matter.
I hope, this helps.
Valeri
This might be of use to somebody. The Readme includes mention of some handy utilities for checking your database files.
https://github.com/SpareSimian/user-group-migration