#!/usr/bin/perl 
use strict;
use warnings;
use Benchmark ':hireswallclock'; # enable hires wallclock (microseconds) timing if possible

my $iterations = 1;

my $regexEngineCode = sub { 
    my $x = "the quick brown fox\n"; $x x= 107374182; print length $x . "\n"; ### 8 bytes less than 2^31.

    my $n=0; ++$n while $x =~ m[^.*$]mg; print $n . "\n"; ### finds all the lines.

    ### Add another line that pushes the length a few bytes over 2^
    $x .= "the straw that broke the camel's back\n"; print length $x . "\n";

    $n=0; ++$n while $x =~ m[^.*$]mg; print $n . "\n"; ### and it silently fails to find any of them.
};

my $time = timeit($iterations, $regexEngineCode);

print "It took ", timestr($time), "\n";

##</code><code>##

2147483641107374182
Out of memory!

real	1m29.931s
user	0m50.376s
sys	0m4.824s

##</code><code>##

#!/usr/bin/perl 
use strict;
use warnings;
use Benchmark ':hireswallclock'; # enable hires wallclock (microseconds) timing if possible

my $iterations = 1;

my $regexEngineCode = sub { 
    my $x = "the quick brown fox\n"; $x x= 107374182; print length $x; ### 8 bytes less than 2^31.

    my $n=0; ++$n while $x =~ m[^.*$]mg; print $n; ### finds all the lines.

    ### Add another line that pushes the length a few bytes over 2^
    $x .= "the straw that broke the camel's back\n"; print length $x;

    $n=0; ++$n while $x =~ m[^.*$]mg; print $n . "\n"; ### and it silently fails to find any of them.
};

my $time = timeit($iterations, $regexEngineCode);

print "It took ", timestr($time), "\n";

##</code><code>##

214748364010737418221474836780
It took 32.7849 wallclock secs (31.79 usr +  1.02 sys = 32.81 CPU) @  0.03/s (n=1)

real	0m32.942s
user	0m31.839s
sys	0m1.129s