You can find that you want in GT::Template
Look for
$ATTRIBS = { func_code => undef, heap => undef, root => '.', strict => 1, compress => 0, begin => '<%', end => '%>', escape => 0, print => 0, stream => 0, cache => 1 };
...near the top.
Look for
$ATTRIBS = { func_code => undef, heap => undef, root => '.', strict => 1, compress => 0, begin => '<%', end => '%>', escape => 0, print => 0, stream => 0, cache => 1 };
...near the top.