Apache2::Filter::HTTPHeadersFixup.3pm

Langue: en

Version: 2005-07-03 (mandriva - 01/05/08)

Section: 3 (Bibliothèques de fonctions)

NAME

Apache2::Filter::HTTPHeadersFixup - Manipulate Apache 2 HTTP Headers

Synopsis

   # MyApache/FixupInputHTTPHeaders.pm
   package MyApache::FixupInputHTTPHeaders;
   
   use strict;
   use warnings FATAL => 'all';
   
   use base qw(Apache2::Filter::HTTPHeadersFixup);
   
   sub manip {
       my ($class, $ra_headers) = @_;
   
       # modify a header
       for (@$ra_headers) {
           s/^(Foo).*/$1: Moahaha/;
       }
   
       # push header (don't forget "\n"!)
       push @$ra_headers, "Bar: MidBar\n";
   }
   1;
 
   # httpd.conf
   <VirtualHost Zoot>
       PerlModule MyApache::FixupInputHTTPHeaders
       PerlInputFilterHandler MyApache::FixupInputHTTPHeaders
   </VirtualHost>
 
   # similar for output headers
 
 

Description

"Apache2::Filter::HTTPHeadersFixup" is a super class which provides an easy way to manipulate HTTP headers without invoking any mod_perl HTTP handlers. This is accomplished by using input and/or output connection filters.

It supports KeepAlive connections.

This class cannot be used as is. It has to be sub-classed. Read on.

Usage

A new class inheriting from "Apache2::Filter::HTTPHeadersFixup" needs to be created. That class needs to include a single function "manip()". This function is invoked with two arguments, the package it was invoked from and a reference to an array of headers, each terminated with a new line.

That function can manipulate the values in that array. It shouldn't return anything. That means you can't assign to the reference itself or the headers will be lost.

Now you can modify, add or remove headers.

The function works identically for input and output HTTP headers.

See the Synopsis section for an example. More examples can be seen in the test suite.

Debug

"Apache2::Filter::HTTPHeadersFixup" includes internal tracing calls, which make it easy to debug the parsing of the headers.

First change the constant DEBUG to 1 in "Apache2::Filter::HTTPHeadersFixup". Then enable Apache-Test debug tracing. For example to run a test with tracing enabled do:

   % t/TEST -trace=debug -v manip/out_append
 
 

Or you can set the "APACHE_TEST_TRACE_LEVEL" environment variable to debug at the server startup:

   APACHE_TEST_TRACE_LEVEL=debug apachectl start
 
 

All the tracing goes into error_log.

Bugs

See Also

Apache2, mod_perl, Apache2::Filter

Author

Philip M. Gollucci <pgollucci@p6m7g8.com>

Previously developed by Stas Bekman.

The "Apache2::Filter::HTTPHeadersFixup" module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.