Take control of your data with associative arrays in Bash: 
If you’ve ever written code, whether it’s a shell script, a Python script, C++, or even Scratch, then you know that variables are vital. Computers and coders use variables as waystations, where they surreptitiously pass information back and forth. For instance, if you need to process a user’s name in a shell script, you might set up a variable, put the username into the variable, and then instruct the computer to do something to the variable (check it against a list of authorized users, for example).
read more: Opensource.com sethkenlon
Supporting Open Source.
Have you tried: Diving with Sharks?