lanx@nc10-ubuntu:~$ perl -e 'CORE::say("bla")' CORE::say is not a keyword at -e line 1. lanx@nc10-ubuntu:~$ perl -E 'CORE::say("bla")' bla lanx@nc10-ubuntu:~$ perl -version This is perl, v5.10.0 built for i486-linux-gnu-thread-multi