Quick question about valid username characters

[Jeff Vian]

Michael Kearey wrote:

> Hi There,
>
> I have several multi-user machines running Redhat 8.0. There are 
> hundreds of usernames on these machines that have mixture of upper and 
> lowercase.
>
> I may be able to just upgrade, but I would prefer to install new 
> Fedora, and automate adding the existing users on old Redhat 8.0 
> machines to new Fedora ones.. (Several reasons for doing this, but not 
> relevent here)

saving the old /etc/passwd and /etc/shadow files will keep your user 
names/passwords as they are, and keeping the /home without reformatting 
it will keep the users data.

After doing the install to FC1, simply put the saved copies of the 
passwd and shadow files back and your users will be back as they are now 
on the older RH 8.0 system.

>
> I have since discovered that Fedora (And Redhat of course) at some 
> stage changed , or maybe more properly, now enforces usernames to 
> allow only lowercase.

AFAIK the only character that was historicaly REQUIRED to be lowercase 
was the first one. (having the user name with the first character in 
uppercase had some strange effects.)

>
> I'd like to know precise details :
>
> Why the change?
>
> Any simple way to circumvent the 'feature' (I know vipw allows you to 
> do it, but I need an automated way !!)
>
> Is there a changelog anywhere in appropriate rpms that explain the 
> change?
>
> Any other advice and info would be much appreciated.

If you are needing to translate the mixed case user names to all lower 
case a simple perl script can do that for you very easily.   It would 
need to work on /etc/passwd and on /etc/shadow to do the translation.
Also, since the home directories are likely named the same as the 
present usernames, you may want to change those as well.  Again, perl is 
your friend for that.