use URI::URL;
print url("foo/test.html")->abs("http://www.sun.com/"),"\n";
print url("/foo/test.html")->abs("http://www.sun.com/"),"\n";
print url("foo/test.html")->abs("http://www.sun.com"),"\n";
print url("http://www.sun.com/foo/test.html")->abs("http://www.sun.com/"),"\n";