Github style split diffs on a command-line

A typical command line is usually not wide enough to handle this kind of comparison. Note that most of Git is built for 80 character wide terminals. So you would have about ~35 characters per side; I doubt that’s helpful (I already have problems reading unified diffs on a much wider terminal).

Git however gives you the ability to use diff tools, external programs that can do whatever diff you prefer. For example, you could use something like WinMerge on Windows, which uses a split view by default. There are many other programs for it, for every platform, and usually every diff program can be set up to work with Git.