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phpuser-agenterror-log

PHP Notice: Undefined index: HTTP_USER_AGENT in line 2

I have added a 3 line code at the top of the index page to eliminate the bad request which occurs in imac devices. The code is given below:

<?php
if (preg_match ("/CaptiveNetworkSupport/", $_SERVER["HTTP_USER_AGENT"])) {
header ("HTTP/1.0 400 Bad Request");
exit ();
}
?>

But I can see lots of "PHP Notice: Undefined index: HTTP_USER_AGENT in " errors in the error_log. How can I remove these logs?

Thanks!

Solution

  • Maybe if you test if the index exists before the preg_match:

        <?php
        if ( isset($_SERVER["HTTP_USER_AGENT"]) && preg_match ("/CaptiveNetworkSupport/", $_SERVER["HTTP_USER_AGENT"]) )
        {
            header ("HTTP/1.0 400 Bad Request");
            exit ();
        }
    ?>