PHP backward compatibility

johnie

Hi. I was wondering whether PHP versions are backward compatible. For example, if i develop a site locally using PHP 4.2 will it work on a host that uses PHP 4.0.6.
We all know that hosts don't always install the latest versions of software.

register_globals is a major difference between versions. What happens if i use $_POST instead of HTTP_POST_VARS like latest versions suggest?

Thanks

John

stuartc1

Basically No, it will not work. you will have to change everything that is not supported manually.

I develop on Win NT / PHP 4.2 but have to deploy to AIX / PHP 4.0 and believe me, I do get some problems. The best way is to keep your script as basic as possible even if it takes a bit longer to code.

'lifes a bitch'
🙂

jayant

Yes, it is possible to do it 🙂

use:

if(!empty($GET)) extract($GET);
else extract($HTTP_GET_VARS);

when we have a url like index.php?id=23&pid=45 and above code at top of php file

we simply use $id and $pid, no need to worry about register_globals or php version 🙂

johnie

I'm not talking just for $HTTP_GET_VARS but in general. Other things that should be considered when using different versions of PHP.

John

the_Igel

If you're writing something big (i.e. not a single script 🙂) it may be useful to make version-compatibility includes. Switching HTTP_POST_VARS/_POST, defining functions, that appeared in newer versions, etc...

johnie

I guess the best solution is to keep an older version for development purposes 🙂
If most of the hosts don't support newer versions then what's the reason for PHP to come with newer versions? Just a rhetorical question 🙂

John

jayant

Because of register_globals on/off,

$_GET / other superglobals are the main difference which cause the major script changes.

we have use $POST instead of $GET and $HTTP_POST_VARS instead of $HTTP_GET_VARS ......... (similarly for other super globals and their corresponding globals)