Member Avatar for assgar

Hi
I need to allow the form user to fill out the form using alpha numeric characters only.
After reading what I could find this my first attempt to use preg_replace.
This works but I need to make sure I am validating the user form input.
Have I missed any thing?

<?php
$find = strip_tags(trim($_POST['find']));
$find = preg_replace("/[%|<|>|!|?|#|*|@|(|)]/", "", $find);
?>
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  • Latest Post Latest Post by Puckdropper
Member Avatar for Puckdropper

Sure, ~.

Perhaps a different solution would work better. Eliminate everything but A-Z, a-z, and 0-9...

Member Avatar for assgar

Thanks for the response

I will use

preg_replace("/[^a-zA-Z0-9\s]+/", "", $find);
Member Avatar for Puckdropper

That better follows the security rule "Only allow what you want to allow, nothing else."

You may want to consider something along the lines of this UNTESTED regexp:
/\W+\s/

This matches one or more nonword characters and a whitespace character. If you have to watch for Unicode characters and foreign input this is the way to go.

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