#expat.pl
#!/usr/bin/perl

use strict;
use warnings;

use Time::HiRes qw( gettimeofday tv_interval );
my $started = [gettimeofday];
END {print STDERR tv_interval($started),"\n";}

use XML::Parser::Expat;

my $parser = new XML::Parser::Expat;
$parser->setHandlers('Start' => \&sh,
                     'End'   => \&eh,
                     'Char'  => \&ch);
$parser->parsefile('tmp.xml');
sub sh {
  my ($p, $e) = @_;
  print $p->recognized_string();
}

sub eh {
  my ($p, $e) = @_;
  print $p->recognized_string();
}

sub ch {
  my ($p, $s) = @_;
  print $s;
}
__END__

#expat2.pl
#!/usr/bin/perl

use strict;
use warnings;

use Time::HiRes qw( gettimeofday tv_interval );
my $started = [gettimeofday];
END {print STDERR tv_interval($started),"\n";}

use XML::Parser::Expat;

my $parser = new XML::Parser::Expat;
$parser->setHandlers('Start' => \&sh,
                     'End'   => \&eh,
                     'Char'  => \&ch);
$parser->parsefile('tmp.xml');
sub sh {
  print $_[0]->recognized_string();
}

sub eh {
  print $_[0]->recognized_string();
}

sub ch {
  print $_[1];
}
__END__

#twig.pl
#!/usr/bin/perl

use strict;
use warnings;

use Time::HiRes qw( gettimeofday tv_interval );
my $started = [gettimeofday];
END {print STDERR tv_interval($started),"\n";}

use XML::Twig;

my $twig = XML::Twig->new (comments => 'drop', pretty_print => 'indent
+ed');

$twig->parsefile("tmp.xml");
$twig->print();
__END__

#twig2.pl
#!/usr/bin/perl

use strict;
use warnings;

use Time::HiRes qw( gettimeofday tv_interval );
my $started = [gettimeofday];
END {print STDERR tv_interval($started),"\n";}

use XML::Twig;

my $twig = XML::Twig->new (comments => 'drop');

$twig->parsefile("tmp.xml");
$twig->print();
__END__

#xslt.pl
#!/usr/bin/perl

use strict;
use warnings;

use Time::HiRes qw( gettimeofday tv_interval );
my $started = [gettimeofday];
END {print STDERR tv_interval($started),"\n";}


use XML::LibXML;
use XML::LibXSLT;

my $parser = XML::LibXML->new();
my $xslt = XML::LibXSLT->new();

my $source = $parser->parse_file('tmp.xml');
my $style_doc = $parser->parse_string(<<EOT);
<?xml version='1.0'?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" versi
+on="1.0">
<xsl:strip-space elements="*"/>
<xsl:output method="xml" indent="yes"/>

    <xsl:template match="@* | node()">
        <xsl:copy>
            <xsl:apply-templates select="@* | node()" />
        </xsl:copy>
    </xsl:template>

    <xsl:template match="comment()" />

</xsl:stylesheet>
EOT

my $stylesheet = $xslt->parse_stylesheet($style_doc);

my $results = $stylesheet->transform($source);

print $stylesheet->output_string($results);
__END__

#make_tmp.pl
#make_tmp.pl
my $cnt = eval(shift());

print <<'*END*';
<?xml version="1.0" encoding="UTF-8"?>
<Node_A>
*END*

while ($cnt--) {
    print <<'*END*';
    <!-- One Line Comment -->
    <Node_B>content
        <!-- Two Line Comment
Two Line Comment-->
        <Node_C>
        </Node_C>
        <!-- One Line Comment -->
        <!-- Multi  Line Comment
  Line 3Comment
  1Line Comment
  2Line Comment
  Line 5Comment
Line Comment-->
    </Node_B>
*END*
}

print <<'*END*';
</Node_A>
*END*
__END__
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make_tmp.pl 3459 creates a 1MB file.