Correctly making a <a href> hyperlink with a variable.

Question

Hi. I'm trying to make a small script for my site where the user would go to the page, lets say, http://example.com/test.php?p=22. From there, a script would read the 'p' variable, and result with a hyperlink going to http://example.com/diffdir/22.exe. So far, this is what I have coded:

<?php
 $test = $HTTP_GET_VARS['p'];
 ?>
 <a href="diffdir/".$test.">Test</a>

Now, I would think that inserthing that $test into the <a href> would do the trick, but sadly the hyperlink only leads to http://example.com/diffdir. Would anyone mind pinpointing what I am doing wrong?

Answer 1

Use $_GET instead of HTTP_GET_VARS, it is deprecated.

And, you need to put the variable into PHP tags:

<a href="diffdir/<? echo $test; ?>">Test</a>

Answer 2

• $HTTP_GET_VARS is deprecated, try use $_GET instead.

• Your 'link' is outside of php tags, by the way, so the interpreter won't execute $test, hence, can't fill in your desired value ..

   <?php  
      $test = $_GET['p'];
   ?>
   <a href="diffdir/<?php echo $test ?>">Test</a>
  

Answer 3

Directly passing data from the URL parameters in $_GET into your HTML output may result in a security threat. Anybody could create a link that leads to your script and passes ANYTHING into the page that the person who is following the link will get, for example harmful javascript code, unwanted ads, etc.

Alway filter input data for possible threats before using it for anything.