Useful links for practicing online
- https://www.shortcutfoo.com/app/dojos/command-line
- http://vim-adventures.com/
- https://www.shortcutfoo.com/app/dojos/vim
- https://www.shortcutfoo.com/app/dojos/regex
- http://www.regexr.com
Test your Linux Basics Knowledge
- http://technicalworldforyou.blogspot.in/2013/06/basic-linux-mcq-questions-for-beginners.html – there are multiple sets whose links you will find at end of quiz. Some questions are dubious though