From funtoo.org
In the UNIX world, we have a lot of options when it comes to editing files. Think of it — vi, emacs, and jed come to mind, as well as many others. We all have our favorite editor (along with our favorite keybindings) that we have come to know and love. With our trusty editor, we are ready to tackle any number of UNIX-related administration or programming tasks with ease.
While interactive editors are great, they do have limitations. Though their interactive nature can be a strength, it can also be a weakness. Consider a situation where you need to perform similar types of changes on a group of files. You could instinctively fire up your favorite editor and perform a bunch of mundane, repetitive, and time-consuming edits by hand. But there’s a better way.
