Renaming the current directory from a shell - possible?

Question

Is it possible to rename the current working directory from within a shell (Bash in my particular case)? If I attempt to do this the straightforward way, I end up with an error:

nathan@nathan-desktop:/tmp/test$ mv . test2
mv: cannot move ‘.’ to ‘test2’: Device or resource busy

Is there another way to do this without changing the current directory? I realize that I can easily accomplish this by changing to the parent directory, but I'm curious if this is necessary. After all, if I rename the directory from another shell, I can still create files in the original shell afterwards.

Answer 1

Yes, but you have to refer to the directory by name, not by using the . notation. You can use a relative path, it just has to end with something other than . or ..:

/tmp/test$ mv ../test ../test2
/tmp/test$ pwd
/tmp/test
/tmp/test$ pwd -P
/tmp/test2

You can use an absolute path:

/tmp/test$ cd -P .
/tmp/test2$ mv "$PWD" "${PWD%/*}/test3"
/tmp/test2$ 

Similarly, rmdir . won't ever work, but rmdir "$PWD" does.

Answer 2

As in @Gilles answer but using brace expansion for brevity:

mv ../{test,test2}

Answer 3

And it depends on how you define “changing the current directory”.

/tmp/test$ (cd .. && mv test test2)
/tmp/test$ pwd
/tmp/test
/tmp/test$ pwd -P
/tmp/test2

spawns a subshell and changes the current directory in the subshell, but leaves your primary shell where it was.