$ perl -IDoc -Ilib -e 'print join(":", @INC), "\n";'
Doc:lib:/usr/lib/perl5/5.8.3/i586-linux-thread-multi:...
$ perl -e 'use lib qw(Doc lib); print join(":", @INC), "\n";'
Doc:lib:/usr/lib/perl5/5.8.3/i586-linux-thread-multi:...