PHP filter_var() question...

[Ichinisan]

I have no formal training in web design, but I'm sometimes asked to make minor changes to the website for the local cableco I work for...and I can usually figure out just enough to get it done.

I need to modify the "Contact Us" page on our site to have a PHP submission form instead of expecting users to have an email client configured on their computer.

I read a bit about the PHP mail() function and made a prototype in no-time. However, this site says I need to use some built-in PHP functions to clean up the email address field, or someone can inject a full email header (specifying CC / BCC fields to send spam).

I don't know how you're supposed to debug or step-through lines of PHP code, so it was very difficult to figure out that the filter_var() function simply don't work. If I understand correctly, it's supposed to be a native PHP function, just like mail().

Here's how I demonstrate that it doesn't work:

echo "<br>Before sanitize:<br>";
echo $email;

//Validate email field
$email = filter_var($email, FILTER_SANITIZE_EMAIL);

echo "<br>After sanitize:<br>";
echo $email;

The first two "echo" lines print out on the page. The last two do not, because the page stops simply rendering after the filter_var() function fails. When I veiw-source in IE8, I can see that no more HTML was transmitted to the browser after first two echo commands.

Then I tried the example from the URL I linked earlier. It basically fails the same way (function doesn't work and page doesn't render).

Can anyone tell me why this doesn't work?

 

[Albatross]

http://php.net/manual/en/function.filter-var.php

what PHP ver do you use?It needs to be 5.2 at least.

 

[Ka0t1x]

Put this right before your code:

error_reporting(E_ALL);
ini_set('display_errors', '1');

Also.. to show the version/info about your PHP install:

<?php
phpinfo();
?>

Above all with PHP if you have any questions/etc about functionality, go to the actual documentation at PHP.net, it will be a life saver.

 

[Ichinisan]

Thanks. I'll have to check it. None of the sites or examples I saw mentioned anything about requring a specific version of PHP.