As for Q1: check your PERL5LIB environmental variable (echo $PERL5LIB). (setting PERL5LIB is a way of including directories that are not normally part of @INC. It lets you customize your environment). You might find some of the directories listed there. You might also want to take a look at your start-up scripts. If they inherit other environments, they too may have PERL5LIB set. As for the -I flag. If it is followed by a list of directories, those directories will be added to the front of @INC for the execution of that script only. It is a way of specifying search directories for individual scripts.

As for Q2: all subdirectories of the directories included in @INC will be searched. In other words, yes, /usr/local/lib/site_perl/lib will be searched.

davidj

update: I am wrong about my answer to Q2. eXile is right. Subdirectories will not be searched. Not sure what I was thinking there :)