Jan 072000

Perl scripts that appear in your browser

Quite some time ago I added a uptime script to one of my web pages.  Someone wrote in saying that when they used the script, the script contents appeared in their browser instead of the uptime results.  At the time, I had no idea what the problem was.   Now I do.

The symptom

If you follow the directions for the uptime script and then browse to your code, but find that you see this on your browser:
use CGI;
$query = new CGI;
print $query->header('text/html');
print `uptime`

then I’ll bet that you browsed to your website without using a virtual host.  I’ll bet you browsed to the machine first.  Then into a directory which contained your script.  That is what causes the problem.  Use a URL instead.

An example

Here’s an example of the problem. 
  1. Browse to http://ww3.freebsddiary.org/ which will give you a directory listing.
  2. Click on the test.freebsddiary.org directory.
  3. Click on the uptime link.

You should now be looking at the script mentioned in the previous section.

If you want to see the script working properly, see http://test.freebsddiary.org/ and click on uptime.

The fix

The solution is to ensure that you are browsing with a virtual host name which corresponds to the cgi-bin directory you are trying to execute.

To be truthful,   I’m not sure of the actual underlying problem, but I think it has to do with ScriptAlias and cgi-bin.  If you know more, please tell me.  I just happened to stumble along on a solution.