multiple distfiles from multiple sources and with multiple compression types

[Rainer Müller]

On 2016-03-26 22:20, René J.V. Bertin wrote:
> On Saturday March 26 2016 02:27:49 Ryan Schmidt wrote:
> 
>> Don't think of them as commands. Think of them as radio buttons.
> 
> Typically that would mean that if you "push" another one of them, the previous choice is undone.
> That doesn't seem to be the case here.
> 
>> Hmm, that could be considered a bug. I think you work around it by setting "use_xz no" as well.
> 
> I could try, but from what I remember of my understanding of the implementation, it was simply not foreseen to unset every possible setting. At least not to go back to the default, use_gz.
> 
>> There was some interest expressed at the MacPorts meeting in Slovenia to make MacPorts automatically detect compression formats during decompression and thus make the "use_xz" etc. options unnecessary. Notably, the tar command in OS X 10.9 (?) and later already supports automatic compression format detection (though we don't use that in MacPorts at this time: we decompress, then pipe the decompressed file to tar).
> 
> That would mean you'd need another method of specifying the suffix, no?

In case of multiple distfiles you will always specify the full name
anyway. This would be that for an option such as this example:

distfiles    foo.tar.gz \
             bar.tar.xz

It is fairly obvious how to extract these files. There is usually no
need to specify how these files should be extracted, since most
compression methods can be deduced from the filename.

The command 'use_* yes' would then only set the extract.suffix
accordingly, instead of the explicit extract.cmd. These two options
would then be equivalent:

use_xz yes
extract.suffix .tar.xz

Rainer