PHP5 and PHP4 are both available on WHB servers. You can already choose to use PHP5 if you want. You can write all new scripts for PHP5, while old scripts can either be rewritten to use PHP5 or left to continue using default PHP4.
On the servers that have PHP4 as default, there are several ways to get your scripts to run using PHP5. Here are two methods:
1. Create an .htaccess file in the script's root folder, containing this line:
AddHandler application/x-httpd-php5 .php .php4 .php3 .phtml
or
2. Use the PHP Configuration function in cPanel to select PHP5.
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