Advanced if-then-else

This chapter is dedicated to everything to do with conditional testing and scripting loops, which are two concepts that are often intertwined. We have already seen the if-then-else loop in Chapter 9, Error Checking and Handling, which focused on error checking and handling. We'll present a small recap of the things we've described regarding if-then-else, before moving on to advanced concepts.

A recap on if-then-else 

If-then-else logic does almost exactly what the name implies: ifsomething-is-the-case, thendo-something or elsedo-something-else. In practice, this could be ifthe disk is full, thendelete some files or elsereport that the disk space looks great. In a script, this could look something like this:

reader@ubuntu:~/scripts/chapter_09$ cat if-then-else-proper.sh 
#!/bin/bash

#####################################
# Author: Sebastiaan Tammer
# Version: v1.0.0
# Date: 2018-09-30
# Description: Use the if-then-else construct, now properly.
# Usage: ./if-then-else-proper...