General and specific make questions

[Ruben de Groot]

On Mon, Jun 08, 2009 at 01:58:57PM -0400, Chuck Robey typed:
> Lars Eighner wrote:
> > 
> > I have some sources which may or may not exist.  My target should be
> > rebuilt
> > if a source exists that is younger than the target.  But sources that do
> > not exist should be ignored and make should not be perplexed over how to
> > create them.  How do I express that kind of relationship?

Have a look at /etc/mail/Makefile. I think that does what you want, e.g. it 
will rebuild the genericstable.db, but only if the genericstable file 
exists and is newer.

Ruben