Problem with Apache/PHP

I am trying to install a problem tracking application (PTS/Keystone from Stonekeep) on to a Linux server.

The requirements for the server/application are:
Apache,
PHP3 (with Apache compiled in as an apache module),
Mysql database


I have created a test file called test.php containing <?PHP_INFO();?>
When I point my browser to the test file located in /usr/local/apache/htdocs, I get the required system information. But if I point my browser to the Keystone file index.php3, in the same location, I get no response at all. If I copy the file from index.php3 to index.php4, and point my browser at it all I get is a display of the physical script, i.e. the actual lines of code, not the screen display.

I have installed PHP4 instead of PHP3 as I was informed that the parser was backward compatible. Is this part of my problem? If so can I install PHP3 and make it co-exist with PHP4, or do I have to scrub PHP4?

Also, I have installed my application in a directory /usr/local/www/data/keystone, do I need to change any parameters in Apache’s configuration to pick up this directory??

>>as I was informed that the parser was backward compatible.

Yes, but you need to specify the AddType line to include whatever extensions explicitly.

Example:
AddType application/x-httpd-php .php .php4

>>can I install PHP3 and make it co-exist with PHP4

Yes, you need to specify "--enable-versioning"

>>do I need to change any parameters in Apache’s configuration to pick up this directory??

Absolutely. Even it's under your DocumentRoot, you at least need to specify with a <Directory> block.

1)I have the following extensions qualified in my httpd.conf:
# For example, the PHP 3.x module (not part of the Apache distribution - see
# http://www.php.net) will typically use:
#
AddType application/x-httpd-php3 .php3
AddType application/x-httpd-php3-source .phps
#
# And for PHP 4.x, use:
#
AddType application/x-httpd-php .php

AddType application/x-httpd-php-source .phps

Do I need to install PHP3? Currently only PHP4 is there. If I do have to,can I do it without stepping all over my current environment?

2)In order to specify "--enable-versioning" do I have to go back ot the begining and do the Congigure,Make and install phase again for apache?

I am sorry if these questions sound very basic, but I very new to the Unix world and am seeking guidance. The suggestions you have made are great but I would be grateful for some more detail.

>>do I have to go back ot the begining and do the Congigure

As I replied to your "co-exist with PHP4" question, that is the case only if you want to compile PHP3 and RECOMPILE PHP4 all over again.

If you like the extension to be named .php3, simply add php3 to this line:
AddType application/x-httpd-php .php .php3
You can even create your very own extension like ".pgill".

My suggestion is that you should keep your PHP4 intact and forget about PHP3.

BTW, have you added that line ->
AddType application/x-httpd-php .php to your httpd.conf yet?
What was the problem? It prompted for download? PHP codes visible from browser source?

In case you want to rebuild PHP, try to build it using DSO. Check out -> http://www.devshed.com/Talk/Forums/Forum15/HTML/000020.html

Addition of the extension worked.

Thank you very much for your help.