prefer local files to network connections

[Karl Berry]

I suggest that tar check if a file exists before trying to make a
network connection. This would eliminate the need for --force-local in
(I expect) most cases. As in:

$ touch foo:bar
$ tar xf foo:bar
tar: Cannot connect to foo: resolve failed

whereas I'd prefer/expect the usual error:
tar: This does not look like a tar archive


Also, since the whole idea of tar making network connections is highly
non-traditional, I also suggest making an environment variable that
turns off the network stuff completely.  TAR_NO_NETWORK or some
such. Since --force-local eliminates the possibility of using
traditional no-dash options, an alias does not suffice. It is not
desirable to make wrapper scripts for something as basic as tar.  Just
an idea/wish ... --thanks, karl.