Period in usernames

[Ian Foster_2]

What's the general feeling about putting periods in unix usernames ?

Our client is moving to a common desktop with active directory and the new windows domain users will be formatted as firstname.lastname - we have been asked if we can create any new unix users with the same naming convention.

I'm not sure about this and would value any thoughts/opinions here.

[Alessandro Pilati]

Ian,
you can create your users with the convention you wrote.

For example:

useradd -u 223 -g users ian.foster

Your default homedir will be /home/ian.foster

I think that you shouldn't have any problem...

Rgds,
Alex

[Jannik · Accepted solution]

thats fine it works ok. your only problem will be that useradd only support 8 characters you you can create the users by hand...
If you har using AD that should work as well.

[Chris Wilshaw]

According to the useradd man page, there shouldn't be an issue with this;

The useradd command may be used with the login argument, where login is the new login name, specified as a string of printable characters. It may not contain a colon (:) or a newline (\n).

I've just run a quick test on one of our dev systems here, and I can confirm that it's worked, and that the ID can successfully log in to the system.

[Marlou Everson]

The pwck(1M) command will complain about a bad character in the login name. It doesn't prevent you from using them. We had a system with periods in the user names and I never had any problems with the logins.

Marlou

[Mel Burslan]

As one of the most clever personal quotes here on ITRC said (can't remember which one):

In theory, there is no difference between theory and practice. But, in practice, there is.

so, if you *CAN* do something does not necessarily mean you should do it. I personally, would try to convince the customer that, this may cause them some headache in the long run. As indicated in the previous post, complaints from app.s like pwck will be an issue. Although in pwck case, this is not a dealbreaker, in some unforeseen circumstances, it may put you in a bad situation. Something you can not predict from today, may start not working after a while, when you need it.

So, in short : proceed with caution ! Slippery road ahead...

[Raj D.]

Hi Ian ,

As posted in this thread , if u try
useradd -u 223 -g users ian.foster

you will get ,
" Login 'ian.foster' is invalid " error.

As it is exceeding 8 character length.


How ever this will work ,
# useradd -u 223 -g users ia.foster

Cheers ,
Raj.

[John E.Ophious]

Howdy Ian,

Periods? Love em. Gives the usernames special character. My favorite of course:

John.E.O

useradd -u 34234 -g cowboys John.E.O

Take care of youself bud,

John E. Ophious

[Ian Foster_2]

Assessment is - can be done - but not necessarily 'recommended'. Erring on the side of caution.