Bash Advanced Variable Idioms for Case Sensitivity Management

Whenever we work with textual strings, sooner or later the issue of case comes up. Does a word need to be fully uppercase, fully lowercase, with a capitalized letter at the start of the word or sentence, and so on. An idiom is a natural language expression of a simple programming task. For example, in the sleep 10 command (which will pause the terminal one is working in for ten seconds), the word sleep is a natural language expression of what is a time based coding construct, developed in the Bash GNU coreutils software package.