Recently, I read here about the :wq! command in vim. I don't understand how it can force-write a file without write permissions. This way, theoretically, one would be able to edit root files without permission. Shouldn't it be disallowed? Or does it write into a new file?
I saw a similar question, but that is about motions and is very different.
P.S. I haven't tried the command for fear of messing up system files.
If you don't have permission to the file (e.g. you don't own the file), then it will not force the write. If you do have permission to the file, but it is a read-only file, then you can force-write it. It's as if you first change the file mode to writable, write your changes, and then change the file mode back to read-only.