filter_var对于URL不正确

Question

i'm trying to use filter_var to validate URLs that have been entered by a user, but it seems not to work in all cases. I've requested a fix for this some time ago on PHP.net, but to no avail.

Besides regexes (yes, a few have been posted on stackoverflow), is there a PHP version that does work or any other method?

The problem I'm facing is that the following string get's validated, which should not:

http://http://www.google.com

Test script:

$url = $_REQUEST['url'];

if (filter_var("http://" . $url, FILTER_VALIDATE_URL)) 

   $filter="true"; 

else 

   $filter="false";

echo "Filter var result of concat with http is:" . $filter . "<br>";

Expected result:

I expect it to return false when i run the script with http://www.google.com and true when i run it with www.google.com

Actual result:

It returns true in both cases

Answer 1

If the bug you reported is anything to go by, filter_var() validates a url by parsing it parse_url() and checking whether the resulting array is sane.

Therefor, glue it back together and validate that they're equal if you want something more strict.

Here's a reasonable glue_url function:

http://doc.habariproject.org/inputfilter_8php_source.html#l00324

Then:

$valid_url = ($url == glue_url(parse_url($url)));

Optionally, also check for "http://$url" if no protocol is supplied.