Re: chown, cpio: proposed change for userspec handling of USER:

[Bob Proulx]

Jim Meyering wrote:
> While writing a few tests for userspec (below), I was surprised to
> re-learn that chown USER_NAME: has a special meaning.  It is a
> shorthand for chown USER_NAME:+$(id -g USER_NAME) ...
> I had expected it to be equivalent to this:
> chown USER_NAME ...

I use it quite often.  It is a convenient shorthand.

> Since the above behavior is not specified by POSIX, and
> is IMHO, counter-intuitive, I propose to change it.  However,
> it is documented both in coreutils and in cpio's manuals.

I disagree about it not being intuitive.  I think it is a very
intuitive use of a default value for the group when the group is not
specified.

> Here's the patch, followed by the coreutils part,
> but I suppose I can't really apply them as-is.
> Rather, I may make "chown USER_NAME: ..." warn-for-now yet
> continue to work and "chown NUMERIC: ..." work like "chown NUMERIC ...".
> Then, in say two years, I'd make the actual change.

I would prefer not to remove this very useful feature.  Of course I
find it useful because I use it quite often.  But I understand that if
it isn't standard then we should remove it from the tool.

Bob