Here's what I have now. I borrowed hdump from the examples directory of HTML::Parser. Then I used CAM::PDF::GS to make a gs log file.

#!/usr/bin/perl 

use strict;
use warnings;
use CAM::PDF;
use Data::Dumper::Concise;
use base qw(CAM::PDF::GS::NoText);

my $file = shift @ARGV;

my $log  = '/root/Desktop/gs.log';
binmode STDOUT, ":encoding(utf8)";

open STDOUT, '>', $log;
my $pdf  = CAM::PDF->new($file);
my $contentTree = $pdf->getPageContentTree(5);
my $gs  = $contentTree->computeGS;
print Dumper($gs):
close STDOUT;
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From the cmdline do

perl gscript.pl /path/to/pdf
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Then I used hdump to examine gs.log:

#!/usr/bin/perl -w

use strict;
use HTML::TokeParser;
use Data::Dumper::Concise;

$| = 1;

sub h {
    my ( $event, $line, $column, $text, $tagname, $attr ) = @_;

    my (@d) = uc( substr( $event, 0, 1 ) ) . " L$line C$column";
    substr( $text, 40 ) = "..." if length $text > 40;
    push @d, $text;
    push @d, $tagname if defined $tagname;
    push @d, $attr if $attr;
    print Dumper(@d);
}

my $p = HTML::Parser->new( api_version => 3 );
$p->handler( default => \&h, "event, line, column, text, tagname, attr
+" );
$p->parse_file( @ARGV ? shift : *STDIN );
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From the cmdline:

perl hdump /path/to/gs.log
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I hope that it's useful for you.