How to create username with "."

[Karl Latiss]

On Thu, 2006-09-21 at 10:47 -0500, Aleksandar Milivojevic wrote:
> Quoting "Miner, Jonathan W (CSC) (US SSA)" <jonathan.w.miner at baesystems.com>:
> 
> > The chown(1) man page says that a colon ":" is the delimiting character:
> >
> > NAME
> >        chown - change file owner and group
> >
> > SYNOPSIS
> >        chown [OPTION]... [OWNER][:[GROUP]] FILE...
> 
> Couple of lines down in the same man page is the following sentence:
> 
> "If the user name is followed by a colon or dot and a group name (or  
> numeric group ID), with no spaces between them, the group ownership of  
> the files is changed as well."
> 
> Chown in Linux uses dot as alternative separator between user name and  
> group name for compatibility with some Unix systems that use dot  
> separator.  Dot was choosen as separator since it is not allowed in  
> user names.  On Unix systems, it is advisable to limit yourself to  
> 8-chars usernames (most utilities will work fine with longer  
> usernames, but not all of them).  And also to limit yourself what  
> characters you are using.
> 
I can't find any documentation that states the dot character is not
allowed in user names.

In fact I have user names with dots, underscores and @ symbols in them
all of which work as expected.

I was also under the impression that the dot separator in chown was
deprecated in favour of the colon, but the man page certainly doesn't
reflect that.

-- 
Karl Latiss <karl.latiss at atvert.com.au>
Atvert Systems