Trouble using dir_config for PerlSetVar inside Perl section

[Larry Leszczynski <la...@furph.com>]

Hi all -

I'm having trouble using server->dir_config in my startup.pl to read
variables set by PerlSetVar inside a Perl section.  I'm using Perl 5.6.1,
Apache 1.3.27, and mod_perl 1.27.

In startup.pl I have:
   my $file = Apache->server->dir_config("CFG") || "";
   warn "Missing path to config file in httpd.conf" unless $file;

In httpd.conf, this works just fine:
   PerlSetVar CFG /path/to/file
   PerlRequire startup.pl

and this works fine too:
   PerlSetVar CFG /path/to/file
   <Perl>
      $PerlRequire = "startup.pl";
   </Perl>

But this does not work (CFG is not set in startup.pl):
   <Perl>
      push @{$Location{"/"}->{PerlSetVar}}, ["CFG", "/path/to/file"];
   </Perl>
   PerlRequire startup.pl

and this does not work either:
   <Perl>
      push @{$Location{"/"}->{PerlSetVar}}, ["CFG", "/path/to/file"];
      $PerlRequire = "startup.pl";
   </Perl>

It seems like this should work, right?  I'm pretty sure the syntax of the
"push" is OK because if I modify the syntax I get a message:
   (2)No such file or directory: <Perl>: PerlSetVar takes two arguments,
   Perl config var and value


Thanks,
Larry Leszczynski
larryl@furph.com

Re: Trouble using dir_config for PerlSetVar inside Perl section

[Larry Leszczynski <la...@furph.com>]

Hi Geoff -

> > and this does not work either:
> >    <Perl>
> >       push @{$Location{"/"}->{PerlSetVar}}, ["CFG", "/path/to/file"];
> >       $PerlRequire = "startup.pl";
> >    </Perl>
> 
[snip]
> 
> what may be happening is that your dynamic configuration may be putting your 
> PerlSetVar into a per-directory scope instead of a per-server scope, since 
> your config is now in a <Perl> section.  meaning, Apache->server->dir_config 
> is (rightfully) empty because now your configuration is in 
> Apache->request->dir_config.  of course, you can't get at $r->dir_config at 
> startup, so you're pretty much SOL.
> 
> try looking at $r->dir_config('CFG') in a request and see if your value is 
> there.  if it is, then I guess my theory is right, and there is little that 
> can be done about it.

Thanks, you're right about what is happening.  Since I need to set the
config file path dynamically in httpd.conf and I need to access it in
startup.pl, I ended up using an environment variable instead:

   PerlPassEnv CFG
   <Perl>
      $ENV{CFG} ||= "/path/to/file";
      $PerlRequire = "startup.pl";
   </Perl>

I had to use PerlPassEnv outside the Perl section - using something like:
   push @PerlSetEnv, ["CFG", "/path/to/file"];
inside the Perl section seems to have the same issues with per-directory
scope as PerlSetVar.


Thanks,
Larry

Re: Trouble using dir_config for PerlSetVar inside Perl section

[Geoffrey Young <ge...@modperlcookbook.org>]

Larry Leszczynski wrote:
> Hi all -
> 
> I'm having trouble using server->dir_config in my startup.pl to read
> variables set by PerlSetVar inside a Perl section.  I'm using Perl 5.6.1,
> Apache 1.3.27, and mod_perl 1.27.
> 
[snip]
> 
> and this does not work either:
>    <Perl>
>       push @{$Location{"/"}->{PerlSetVar}}, ["CFG", "/path/to/file"];
>       $PerlRequire = "startup.pl";
>    </Perl>
> 
> It seems like this should work, right?  

you may be running into an odditity of PerlSetVar.  internally, mod_perl has 
logic to merge per-server and per-directory PerlSetVar attributes, doing it 
itself instead of relying on Apache. while this is good under most 
circumstances, I think you've uncovered someplace where it doesn't work as 
well as you'd like.

what may be happening is that your dynamic configuration may be putting your 
PerlSetVar into a per-directory scope instead of a per-server scope, since 
your config is now in a <Perl> section.  meaning, Apache->server->dir_config 
is (rightfully) empty because now your configuration is in 
Apache->request->dir_config.  of course, you can't get at $r->dir_config at 
startup, so you're pretty much SOL.

try looking at $r->dir_config('CFG') in a request and see if your value is 
there.  if it is, then I guess my theory is right, and there is little that 
can be done about it.

HTH

--Geoff