This is a cheatsheet for the defacto standard for editing files in Linux / Unix at the terminal or command line. Admittedly, it can be intimidating and frankly confusing to get started if you never have used it; however, it comes with nearly every installation of an operating system based on Unix. As a result, it can pay to learn at least the basics of how to use vi. It can really come in handy in a pinch and, with time, you may find it very useful and much faster to use then a more full featured text editor like UltraEdit / NotePad++ / etc.
And if you consider yourself a vi expert, then maybe you’d be interested in this t-shirt