bug#15421: RFE: 'id +NNN' for getting group data from a uid rather than username

[Jim Meyering]

On Thu, Sep 19, 2013 at 12:13 PM, Eric Blake <address@hidden> wrote:
> I just created a local user named "0" (don't ask), and noticed that
> although we can do things like "chown +0:+0 file" to FORCE a file to be
> owned by uid 0 (rather than the uid of my unfortunate "0" username),
> it's a bit harder to learn details about a uid hidden by a poor username.
>
> $ id 0
> uid=14987(0) gid=14987(0) groups=14987(0)
> $ id +0
> id: +0: no such user
>
> Of course, everyone "knows" that uid 0 is named "root", but this
> question applies to any other unfortunate uid/name collision.
> Therefore, I propose that we support 'id +0' as the way to say 'give me
> the details about uid 0, no matter if username 0 also happens to exist'.

Makes sense, and like the chown "feature", it should be safe.