How to copy a string and paste a substring in Emacs?

Question

Found this on the interwebs:

(defun clipboard/set (astring)
  "Copy a string to clipboard"
   (with-temp-buffer
    (insert astring)
    (clipboard-kill-region (point-min) (point-max))))

I want to make it interactive, run the string through substring, and then copy it to the clipboard

(defun clipboard/set (astring)
  "Copy a string to clipboard"
(interactive)
(let (bstring (substring astring -11)))   
(with-temp-buffer
    (insert bstring)
    (clipboard-kill-region (point-min) (point-max))))

How would one do this?

Answer 1

You need to tell interactive how to populate the arguments:

(interactive "sAstring: ")

Also, the syntax of let is different, it starts with a list of lists of variables and values, ie

(let ((bstring (substring astring -11)))
;    ^^

ie

(defun clipboard/set (astring)
  "Copy a string to clipboard"
  (interactive "sAstring: ")
  (let ((bstring (substring astring -11)))
    (with-temp-buffer
      (insert bstring)
      (clipboard-kill-region (point-min) (point-max)))))

and close it at the very end.