[Nix-dev] restricted downloads

[Marc Weber]

Excerpts from Eelco Dolstra's message of Sun May 02 23:23:14 +0200 2010:
> Hi,
> 
> On 04/30/2010 10:47 PM, Yury G. Kudryashov wrote:
> 
> > I've just commited support for "restricted downloads" in fetchurl. The idea 
> > is that you can write
> > src = fetchurl {
> >   url = "http://restricted.noltd/download.html";
> >   name = "my_restricted_src.zip";
> >   restricted = true;
> >   sha256 = "myhash";
> > };
> 
> This is an abuse of fetchurl.  You should have a different fixed-output
> derivation function that always fails (say, `requireFile { name = ...; sha256 =
> ...; errorMessage = ...; }')  - there is no need to use fetchurl for this purpose.
> 

Something like this?

Maybe people download stuff into /tmp anyway?

fetchurlRestricted = {name, sha256, info ...}@args:
  let path = "/tmp/manual-download-required/${name}";
  if builtins.pathExists path
  then stdenv.fetchurl (args //  { url = "file://${path}"; } );
  else throw "create path ${path}: ${info}";

where info is something like
"goto www.game.com, click on download, accept license, download xx.y file"


This would be 

Marc Weber