Presentations
https://www.slideshare.net/nishant_munjal/introduction-to-unix-119441071
https://www.slideshare.net/nishant_munjal/vi-editor-119441072
https://www.slideshare.net/nishant_munjal/shell-programming-concept
https://www.slideshare.net/nishant_munjal/unix-administration-119441074