gistfile1.txt

#!/usr/bin/perl

use strict;
use warnings;

my $string = 'x' x (1024 * 1024 * 8);

print "Before match\n";

$string =~ /x/;

print "After plain match\n";

$string =~ /(x)/;

print "After capturing match\n";

__END__
mhorsfall@darmstadtium:~$ perl -d:MemoryTrace::Light tm.pl
>> 11608 main, tm.pl (6) used 16752640 bytes
Before match
After plain match
>> 11608 main, tm.pl (14) used 8380416 bytes
After capturing match