usernames

[kwall@kurtwerks.com]

On Tue, Oct 29, 2002 at 12:19:34PM -0500, Randy Donohoe wrote:
> In trying to set up sendmail on Libranet 2.7 we're having problems with 
> periods in usernames. Libranet won't let you use periods in usernames, 
> so we're going in to the password files and changing them manually. Are 
> we creating security problems? Why won't some programs let you use 
> puncuation marks? 

Because periods and other punctuation marks are typically used
in regular expressions, so processing usernames with, say, !
in it becomes quite interesting and requires special handling.
For example:

$ export UNAME="kurt!wall"
bash: !wall": event not found

Here, Bash treats "!" like as it would when doing command history
searches. The grep command (actually, anything that uses regular
expressions) treats "." as a placholder for any single character,
which can create aggravating problems in text utilities.

Kurt
-- 
Kansas state law requires pedestrians crossing the highways at night to
wear tail lights.