As a part of school assignment, I wrote a self-expanding archive creator in the form of a UNIX shell script. The script should be POSIX-compatible, it’s very well documented, and features some interesting processing of its own source code.
It’s not a secret that files are not really deleted when you tell the operating system to remove them. References to the files are removed but the data stays and can be sometimes retrieved. This can save your life when you delete something you shouldn’t have. Sometimes, however, you need to deal with data that must not see the light of the day ever again.
Long bus rides are boring. Way boring. Unless you happen to like mathematics and there is a digital clock on the bus.