Thank you for pointing out Test::LeakTrace. I have tried this now, using the code from the CPAN example, but I do not receive any report.

use warnings;
use strict;
use diagnostics;
use HTML::FormatText;
use HTML::TreeBuilder 5 - weak;
use constant HAS_LEAKTRACE => eval{ require Test::LeakTrace };
use Test::More HAS_LEAKTRACE ? (tests => 1) : (skip_all => 'require Te
+st::LeakTrace');
use Test::LeakTrace;
leaks_cmp_ok{
open INPUT, "< D:/websiteadresses.txt" or die "Problem: $!";
#The file contains 28000 addresses of websites (each one on a new line
+)
my @INPUT=<INPUT>;
close INPUT;
while (@INPUT) {
 my $input=shift(@INPUT); 
  chomp $input;
 print $input;
 my $content=HTML::FormatText->format_file($input, leftmargin => 0, ri
+ghtmargin => 50);
 # This is followed by regular expressions, the results of which are s
+aved in a new file; all of this is disabled now.
 }
} '<', 1;
[download]

The program just runs out of memory after about 3000 runs through the while-loop, but the program output is not followed by any report from LeakTrace. I also did not see a reference to a file in which the report is saved, etc. on the CPAN documentation for Leaktrace. Not sure what to do now...

I am running this in ActiveState's Komodo, but there is not output from Leaktrace either in the internal output window in Komodo nor in the external shell