Underscores in some directory user, group names (Postfix MacPort example)

[Jordan K. Hubbard]

This is because the original designers of Unix neglected to take into  
account the notion of user namespaces - the namespace is flat.  That  
means that system or role specific names can conflict with names that  
users would like to use for themselves (c.f. "admin" or "operator")  
unless you adopt a convention for keeping them separate.  That  
convention is the prefix underscore.

- Jordan

On Jan 4, 2008, at 5:29 PM, Tabitha McNerney wrote:

> Hello all --
>
> I just installed the current version of the Postfix port (version  
> 2.4.6) on a Leopard Server system.
>
> After the install, I noticed a username and group name of "_postfix"  
> and "_postdrop" respectively, as in:
> drwx--x---  2 _postfix  _postdrop  102 Jan  4 23:06 public/
> drwx-wx---  2 _postfix  _postdrop  102 Jan  4 23:06 maildrop/
> This differs from previous Postfix port installations (UID 27 was  
> "postfix" not "_postfix"). This isn't really a MacPorts specific  
> issue but I'm wondering if anyone knows why Apple changed their  
> naming schema on Leopard, for short names such as:
>
> from "postfix" to "_postfix"
>
> ?
>
> I wonder if this has something to do with becoming fully UNIX  
> compliant? POSIX?
>
> Mr. Jordan Hubbard, can you offer some wisdom and perspective on  
> this subject?
>
> Thank you,
>
> T.M.
>