Redefine Built in PHP Functions

Question

I would like to redefine certain functions in PHP that are already built for example, echo() or time() - I don't need to define these functions globally, just within a single script for testing.

I think this can be done in Perl but in PHP - Is this possible?

Answer 1

runkit_function_redefine — Replace a function definition with a new implementation

Note: By default, only userspace functions may be removed, renamed, or modified. In order to override internal functions, you must enable the runkit.internal_override setting in php.ini.