Learn Linux Shell Scripting - Fundamentals of Bash 4.4

Type checking

Something we've done in many of our scripts is checking arguments. We started our library with a function that allowed checking the number of arguments the user gave as input. Another action we frequently performed on user input was validating the input type. If our script requires a number, for example, we'd like the user to actually enter a number and not a word (or a written out number, such as 'eleven'). You might remember the approximate syntax, but I'm sure that by now if you needed it again, you would look through our older scripts to find it. Doesn't that sound like the ideal candidate for a library function? We create and thoroughly test our function once, and then we can feel safe just sourcing and using it! Let's ...