为什么echo（）输出的base64_decode（）无法在浏览器中完全显示？

Question

please see the code below :

<?php
$str = 'PD9waHANCiRzdHJpbmcgPSAiYmVhdXRpZnVsIjsNCiR0aW1lID0gIndpbnRlciI7DQoNCiRzdHIg
PSAnVGhpcyBpcyBhICRzdHJpbmcgJHRpbWUgbW9ybmluZyEnOw0KZWNobyAkc3RyLiAiPGJyIC8+
IjsNCg0KZXZhbCgiXCRzdHIgPSBcIiRzdHJcIjsiKTsNCmVjaG8gJHN0cjsNCj8+IA==';
echo base64_decode($str);
?>

this is a simple php code and you can decode base64 string by using the URL below :
http://www.base64decode.org/

why base64_decode() function in this example can not do it's job. the output is like below :

"; eval("\$str = \"$str\";"); echo $str; ?>  

instead of :

<?php
$string = "beautiful";
$time = "winter";

$str = 'This is a $string $time morning!';
echo $str. "<br />";

eval("\$str = \"$str\";");
echo $str;
?> 

what is the problem and how can i fix it for big codes?

EDIT :
there is an invisible part of output and i can find it by page source.
but why do we have this reaction?
thanks in advance

Answer 1

The problem is that you're viewing it as HTML. If you look at the source or pass a header to make the browser interpret it as text, you'll see the whole thing.