Elisp function for getting position in files + an opinionated keybinding

get-file-path.el

(require 'cl-lib)

(defun get-current-file-path (prefix)
  "Get filesystem from current buffer, provided it's a file buffer. With
prefix 4 also append line number. With prefix 16 append column number to
everything. Put the resulting string in the kill-ring and also display
it int the minibuffer."
  (interactive "p")
  (let* ((file-name (buffer-file-name (current-buffer)))
         (position (when (>= prefix 4) (list ":" (int-to-string (line-number-at-pos)))))
         (position (if (>= prefix 16) (append position (list ":" (int-to-string (current-column)))) position)))
    (if file-name
	(let ((file-name-and-line (apply #'cl-concatenate 'string file-name position)))
	  (kill-new file-name-and-line)
	  (message file-name-and-line))
      (message "Not a file buffer. Cannot get path and line number."))))

(keymap-global-set "M-g M-f" 'get-current-file-path)