Images: (Brian Kernighan) https://upload.wikimedia.org/wikipedia/commons/a/ae/Brian_Kernighan_in_2012_at_Bell_Labs_1.jpg (Unix Penguin) https://cdn.educba.com/academy/wp-content/uploads/2018/08/UNIX-interview-questions.jpg (Unix ) https://www.guru99.com/images/man_man_1.png (all other images) shutterstock.com
Sources: http://kernighan.com/ https://en.wikipedia.org/wiki/Brian_Kernighan https://en.wikiquote.org/wiki/Brian_Kernighan