# store a reference to a sub
my $coderef = sub
{ 
  print shift || "Foo";
  print "\n";
};

# execute code, with or without arguments
$coderef->();
$coderef->('Bar');
$coderef->();

##</code><code>##

my $code =<<'CODE';
  print shift || "Foo";
  print "\n";
CODE

my $coderef = eval"sub{$code}";