Re: Some questions about make

[CHEN Cheng]

On Sun, Jul 12, 2009 at 03:17:24PM -0400, Paul Smith wrote:
> On Fri, 2009-07-10 at 00:37 -0700, 雷 高 wrote:
> > I am learning GNU make by the make manual. I have some questions about
> > make:
> 
> You should be using the normal make help mailing list; sending email to
> me directly just means it will take that much longer to get a response.

Paul is nice.

> 
> > 1. When a file doesn't exist as the prerequisite and can't be made by
> > implicit rules,make will stop and output an error. But when the file
> > doesn't exist as the target and the command for that rule can't create
> > the file, such as “foo : ;echo hello”, the file is considered as
> > existing files.My question is that how does make treat none existing
> > files..
> 
> I don't understand this question.

If I understand the question correctly, the following might be useful:

    A target is out of date if it does not exist or if it is older than any
    of the prerequisites (by comparison of last-modification times).
    -- from gmake manual section 4.2 Rule Syntax


-- Cheng