There doesn't appear to be a way to get the filename of code that is currently executing. 

Eg. echo $SCRIPT_FILENAME; or echo $PHP_SELF; 
works fine in most situations, but as soon as the file containing this code is included in another, they start to return the filename of the includING file. (not the includED one).

I understand this generally goes against the purpose of include() but this functionality would be very useful. 

Thanks