HOWTO: Use q, qq, qr and qx string quotation operators in Perl

q  -- single quotes, no variable interpretation
qq -- double quotes, enable variable interpretation
qr -- regular expression like quotes
qx -- back-quotes, execute external command placed within

HOWTO: Install packages for Perl

1) Start CPAN shell

    sudo /usr/local/bin/cpan

2) Install module

    install Module::Build

3) Exit CPAN shell

    exit