Running some functions from emacsclient doesn't work

Question

This works:

emacsclient  -s emacs -e "(call-interactively 'find-file)"

But this one doesn't:

emacsclient  -s emacs -e "(call-interactively 'newline)"

In fact, none of the functions I tried to run via Terminal with emacsclient didn't work except find-file. Built-in functions tend to turn nil while functions I wrote tend to turn errors like *ERROR*: End of buffer, although I can run the same function directly in emacs without any problem.

The function that turned the above error message is this:

(defun test (&optional args)
  (interactive )
  (forward-char 2)
)

How can I get this to work?

OS X 10.8 Emacs 24.5 (9.0) desktop version

Answer 1

What buffer do you think emacsclient runs the command in?

$ emacsclient -e '(current-buffer)' 
#<buffer  *server*>

The server uses the  *server* buffer for its buffer-local variables. Its contents are only used for debugging purposes.

What you're trying to do doesn't make sense: things like inserting a newline and moving the cursor only make sense if you specify which buffer to act in. If you want to act in an already-open buffer, you need to select it first with set-buffer, e.g.

emacsclient -e '(with-current-buffer "my-already-open-file" (forward-char))'