如何在我的服务器安装PHP中添加特定的PHP函数

I am running PHP version 5.1.6 currently, but I would have an application which makes pretty heavy use of the json_encode and json_decode functions, as such, I would like to add these functions to my server's install of PHP (as these functions only ship with PHP versions PHP 5.2 +)

What is the best way of doing this. I'm not too down with the whole Terminal approach so if there was another way that would be great

Many thanks in advance

If you're unable to upgrade, use PEAR's Services_JSON. It works as of PHP 4.3 so you should be fine.

Maybe you should put somewhere in the root of your application a call to a checker function that does function_exists() for a couple of your needed function and if not stops the execution to prevent unwanted results.