A few scripts that covers all the basic concepts in bash scripting. -- 2

A script that covers all the basic concepts in bash scripting. Now this may not be possible with a single script but a few scripts. The idea is to create a reverse engineered tutorial for shell scripting. The script needs to these two important aspects. 1) It should cover as many concepts as possible (concepts like variables, conditionals and loops in one script and maybe others in another script) 2) The script should have a practical purpose (a script that would be used in the industry). I would also require very brief explanations of these concepts. and comments. The script and concept explanations should not have any previous copyright or IP associated with it. Every Scripts should be written in the most efficient manner (less lines of code for example) and should be well documented in terms of inline script comments and the concept explanations We start with the first 3 use cases that best suite using shell scripts.