is there any way to find php application is compatible with particular version or not

I have one big php application running on php 4 but I want to move this application on php 5.2 but I am not sure whether it's all functionally work on it or not as I don't want to test full application again. So I want to know is there a way to开发者_开发问答 find out compatibility of application with php versions.

PHP5 come with major changes, I don't think there's such an automated way to check compatibility out there..

You'll have to check all files manualy. use batch file text seach (and replace?) tools to look for functions, classes etc.

here's your guide to start

Unfortunately, you're going to have to test it. You can at least use the PHP changelog as a bit of a checklist to see if any code in application is affected.

PHP 4 to PHP 5 was a pretty huge leap; it's probably a safe bet your app was affected even before you go through testing.

You can use online tool for checking syntax compatibility of your code php 4 and php 5.2,5.3. For manual checking read Migrating from PHP 4 to PHP 5.0.x .