How to quickly switch between two versions of a file In more detail, I need to have a simple command or something else that I can trigger that will switch a certain file between two versions. The two file versions will not change, just need to switch which one of them is "active" and accessible by other programs. The file needs to stay in its current location, with the same name, just some of the contents need to be adjusted. 
Is there a quick way to do this?
It sounds like you need to have the files open in an editor that will display both files at once or have windows for each file. 2 editors I know of are Atom and Visual Studio Code. These editors allow you to display 2 files side-by-side and you can edit whichever one you want.