Most internal functions have been rewritten so they
return TRUE when successful
and FALSE when failing, as
opposed to 0 and -1 in PHP/FI 2.0, respectively. The new
behaviour allows for more logical code, like $fp = fopen("/your/file") or fail("darn!");.
Because PHP/FI 2.0 had no clear rules for what functions
should return when they failed, most such scripts will
probably have to be checked manually after using the 2.0 to
3.0 convertor.