Underscores changed to hyphens by HTTP::Proxy header filter

jds17 has asked for the wisdom of the Perl Monks concerning the following question:

Hi, I have written a simple HTTP Proxy which I want to use to add an entry to the header of every request passing through it. My problem is that all underscores "_" get changed to hyphens "-" in the entries' keys and the key is converted to lowercase. The code looks as follows:

The ini file:

[proxy_setup]
#port on which proxy listens, use in browser proxy settings
port=84
#header to add
header_key=SM_USER
header_value=waldo
[download]

The proxy:

use HTTP::Proxy;
use HTTP::Proxy::HeaderFilter::simple;
use HTTP::Proxy::Engine::NoFork;
use Config::IniFiles;

#initialize ini file loading
my $ini = 'SM_Proxy.ini';
my $cfg = new Config::IniFiles(-file => $ini);
die "invalid ini file $ini" unless defined($cfg);

#reads specified config file entry
sub read_cfg {
  my ($section, $key) = @_;
  my $val = $cfg->val($section, $key);
  die "undefined key $key in section $section" unless defined($val);
  $val;
}

#read values from ini file
my $port = read_cfg('proxy_setup', 'port');
my $header_key = read_cfg('proxy_setup', 'header_key');
my $header_value = read_cfg('proxy_setup', 'header_value');

#define proxy and header filter(adding entry read from ini file to eac
+h request header)
my $proxy = HTTP::Proxy->new( host => "127.0.0.1", port => $port );
my $filter = HTTP::Proxy::HeaderFilter::simple->new(
  sub { $_[1]->header( $header_key => $header_value); }
);
$proxy->push_filter( request => $filter );
$proxy->start;
[download]

I.e. in the current example, the name of the header entry comes out as "sm-user" instead of "SM_USER". What am I doing wrong?

Update: Thank you guys, using the flag $HTTP::Headers::TRANSLATE_UNDERSCORE solved the issue!

Comment on Underscores changed to hyphens by HTTP::Proxy header filter Select or Download Code

Replies are listed 'Best First'.
Re: Underscores changed to hyphens by HTTP::Proxy header filter by Anonymous Monk on Apr 09, 2009 at 09:55 UTC
HTTP::Header `#!/usr/bin/perl --- use strict; use warnings; use HTTP::Headers; my $h = HTTP::Headers->new; $h->header( qw' SM_USER waldo '); print $h->as_string; __END__ SM-USER: waldo` [download] http://cpansearch.perl.org/src/GAAS/libwww-perl-5.825/t/base/headers.t `# Check with FALSE $HTML::Headers::TRANSLATE_UNDERSCORE { local($HTTP::Headers::TRANSLATE_UNDERSCORE); $HTTP::Headers::TRANSLATE_UNDERSCORE = undef; # avoid -w warning $h = HTTP::Headers->new; $h->header(abc_abc => "foo"); $h->header("abc-abc" => "bar"); ok($h->header("ABC_ABC"), "foo"); ok($h->header("ABC-ABC"),"bar"); ok($h->remove_header("Abc_Abc")); ok(!defined($h->header("abc_abc"))); ok($h->header("ABC-ABC"), "bar"); }` [download]	[reply] [d/l] [select]
Re^2: Underscores changed to hyphens by HTTP::Proxy header filter by Anonymous Monk on Apr 09, 2009 at 09:59 UTC
http://cpansearch.perl.org/src/GAAS/libwww-perl-5.825/Changes `HTTP::Headers now special case field names that start with a ':'. This is used as an escape mechanism when you need the header names to not go through canonicalization. It means that you can force LWP to use a specific casing and even underscores in header names. The ugly $TRANSLATE_UNDERSCORE global has been undocumented as a result of this.` [download] seems to work `#!/usr/bin/perl --- use strict; use warnings; use LWP 5.800; my $h = HTTP::Headers->new; $h->header( qw' :SM_USER waldo '); print $h->as_string; __END__ SM_USER: waldo` [download]	[reply] [d/l] [select]