Re: [PATCHv2/RFC] gitweb: Prepare for splitting gitweb

On Wed, 7 Jul 2010, Jakub Narebski wrote:

On Wed, 7 Jul 2010, Ævar Arnfjörð Bjarmason napisał:

quoted

On Wed, Jul 7, 2010 at 09:57, Jakub Narebski [off-list ref] wrote:

quoted

[...]
 use strict;
 use warnings;
+
+use File::Spec;
+# __DIR__ is taken from Dir::Self __DIR__ fragment
+sub __DIR__ () {
+       File::Spec->rel2abs(join '', (File::Spec->splitpath(__FILE__))[0, 1]);
+}
+use lib __DIR__ . '/lib';
+

What was the result of the discussion about using __DIR__ again? You
only need to use that method when you call a perl program whith *then*
includes a module. If you just need to add the lib/ directory relative
to the script you're invoking you can use FindBin:

    use FindBin qw($Bin);
    use lib "$Bin/lib";

It's

      use lib "$Bin/../lib";

(I don't like this ../lib here, but that's my personal preference).

Actually for gitweb, where gitweb.cgi is put in "top" directory, and
lib/ directory is in the same directory that the script is, it would
be

        use FindBin qw($Bin);
        use lib "$Bin/lib";

The documentation says that $FindBin::Bin is

        $Bin    - path to bin directory from where script was invoked

so it is path to directory, not to script itself.

If it worked...

But you might be right that I am overly cautious in avoiding FindBin.
It is nowadays not recommended solution (on #perl, for example), but
it is perhaps true that the conditions where it fails are not fulfilled
for the case of gitweb.

Or perhaps not:

  KNOWN ISSUES

  If there are two modules using FindBin from different directories
  under the same interpreter, this won't work. Since FindBin uses a
  BEGIN block, it'll be executed only once, and only the first caller
  will get it right. This is a problem under **mod_perl** and other
  persistent Perl environments, where you shouldn't use this module.

Gitweb can be used under mod_perl (to be more exact ModPerl::Registry).

I wrote simple script that tests result of __DIR__ and $FindBin::Bin.
For cgi-bin / mod_cgi it was:

  __DIR__       = /var/www/cgi-bin/gitweb (symlink to /home/local/gitweb)
  $FindBin::Bin = /home/local/gitweb

For mod_perl (ModPerl::Registry handler) it was

  __DIR__       = /var/www/perl/gitweb (symlink to /home/local/gitweb)
  $FindBin::Bin = /

As you can see it's useless.  I have't checked the FastCGI case...

-- 
Jakub Narebski
Poland