Question

I have searched around but I am not very experienced with PHP. The script I have at the moment is

<?php
 $to = "my email address";
 $subject = "Report for broken link";
 $id= $_GET['id'];
 $body = "Link ID: $id";
 if (mail($to, $subject, $body)) {
    echo("<p>Message sent!</p>");
  } else {
   echo("<p>Message delivery failed...</p>");
  }
 ?>

So basically it is for a user of the site to report a broken link, but I expect this is very easily exploitable as everytime I refresh the .php page an e-mail is sent.

As in the question title, I am looking for a way to limit use of the .php file to once per day (or per x hours) per user. What is the easiest way to do this?

EDIT: or, if you have a better idea for a solution, please let me know!

EDIT AFTER HAVING SOLVED:

For those interested in the solution to this, I have used the following (it seems to work, but if anyone can see any glaring holes in it please post her):

<?php
 $to = "my email address";
 $subject = "Report for broken link";
 $id= $_GET['id'];
 $body = "Link ID: $id";
 if(isset($_COOKIE['noaccess'])) {
 echo ("<p>Message already sent!</p>");
  } else {
     if (mail($to, $subject, $body)) {
       setcookie("noaccess", "2hrs", time()+7200);
       echo("<p>Message sent!</p>");
      } else {
       echo("<p>Message delivery failed...</p>");
      } }
 ?>

Answer 1

One thing you could try is after the email is sent store a timestamp in the user session or a browser cookie, and then when the script is invoked again, you can check to see if a timestamp is present and if yes, if it is higher than your email threshold (one day, x hours, etc…)