#!/usr/bin/perl -w

use strict;
use warnings;


sub myfunc_1
{
  my $A = '';
  vec($A, 20000000, 8) = 0;
  return $A;
}

sub myfunc_2
{
  vec($_[0], 100000000, 8) = 0;
  return 0;
}

$b = <STDIN>;
my $BIGSTRING = '';
myfunc_2($BIGSTRING);        # memory usage is normal.
$b = <STDIN>;

undef $BIGSTRING;
# Pff! Gone from memory! TINYPERL.EXE memory
# usage visibly shrinks in Windows Task Manager.
$b = <STDIN>;

my $STRING2 = myfunc_1();    # memory usage is double!
$b = <STDIN>;

undef $STRING2; # Deletes one copy only

$b = <STDIN>;


##</code><code>##


#!/usr/bin/perl -w

use strict;
use warnings;

sub MemoryEaterFunc
{
  my $A = '';
  vec($A, 20000000, 8) = 0;   # Create a large string
  $A .= $_[0];                # Add to it. Do something.

# Evaluate the last statement,
# and that is the return value of the sub! even if
# you don't write return $A; it still returns it.
# If you want the function to not return the big string,
# then put 'return 0;' at the end of the sub.

}

$a = <STDIN>;
MemoryEaterFunc(2);  # Eats memory and doesn't release it
$a = <STDIN>;


##</code><code>##


sub MemoryEaterFunc_FIXED
{
  my $A = '';
  vec($A, 20000000, 8) = 0;   # Create a large string
  $A .= $_[0];                # Add to it. Do something.
  undef $A;
}