How To Find BASH Shell Array Length ( number of elements ) - nixCraft
Using test Command in Bash Scripts
How to use Variables in Bash Programming
bash - How to determine whether a argument is string or number in a shell script? - Stack Overflow
Bash Append Text To a Variable (Concatenate Strings) - nixCraft
How to Convert Strings into Numbers in Bash
String Manipulation in Shell Scripting - GeeksforGeeks
Bash variables - Things that you probably don't know about it | Unboxing the Cloud
How would you convert a string into an integer in Bash? - Quora
Bash Variables - Javatpoint
How to Subtract an Integer from a Variable – Bash
How to Argument String to Integer in Bash? – Its Linux FOSS
String Manipulation in Shell Scripting - GeeksforGeeks
Shell Script to Validate Integer Input - GeeksforGeeks
Bash Scripting - String - GeeksforGeeks
Using test Command in Bash Scripts
Declaration of Variables and Constants with Bash Scripting
How to Compare Strings in Bash | Linuxize
A nice way to return string values from functions in Bash | #define me human
How to Convert Strings into Numbers in Bash
Unix & Linux: Argument string to integer in bash (4 Solutions!!) - YouTube
Bash see if an input number is an integer or not - nixCraft
