Most mod_perl handlers use the perl-script handler. Here are a few things to note:
PerlOptions +GlobalRequest is in effect unless:
PerlOptions +SetupEnv is in effect unless:
STDOUT and STDOUT get tied to the request object $r, which makes it possible to read from STDIN and print directly to STDOUT via print( ), instead of having to use implicit calls like $r->print( ).
Several special global Perl variables are saved before the handler is called and restored afterward (as in mod_perl 1.0). These include %ENV, @INC, $/, and STDOUT's $| and END blocks.