How to Search for Text Within Files and Folders in Linux

If you are a developer, a web programmer, or someone who works with many files and you need to find a single piece of text, you should know and memorize a single command you can use on any Linux-based system.

For example, let’s say you have a directory containing 30 folders and 20,000 files. It doesn’t matter the extension of the files contained in these folders as they can be whatever crosses your mind, e.g. .txt, .php, .css, .js, etc.