"unless( $ENV{+ __FILE__ } eq __FILE__ ){"

##</code><code>##

BEGIN {
    unless( $ENV{ +__FILE__ } eq __FILE__ ){
        delete $ENV{LIBPATH};
        $ENV{ +__FILE__ } = __FILE__;
        exec $^X, __FILE__, @ARGV; 
   }
}

##</code><code>##

BEGIN {
    if (exists $ENV{LIBPATH}) {
        delete $ENV{LIBPATH};
        exec $^X, __FILE__, @ARGV;
    }
}

##</code><code>##

    "unless( $ENV{+ __FILE__ } eq __FILE__ ){"