Example

> redit("redit.r", "emacs");
edited and loaded rfile: redit.r
> system("diff redit.r redit.r.~1~");
28c28
<     ED = "emacs";
---
>     ED = "vi";
32c32
<       error ("2nd argument to edit() must be string");
---
>       error ("2nd argument ot edit() must be string");