How do I log M-x usage in emacs?

Question

I want to log my usage of M-x in emacs to a file so that I can see which functions I should learn the shortcut to / bind a shortcut for. This would preferably just append the names of the used functions to a file/emacs-buffer, maybe with a timestamp, so that I can see in what context I use them. Does anyone know how to solve this?

Answer 1

I would suggest adding an advisory function to execute-extended-command, and another to read, such that when execute-extended-command is being run, anything read in the minibuffer is logged to your defined buffer with a timestamp.

I have been meaning to learn how to use advise, so I will be editing this comment later with working elisp code once I have code that does this (should be less than ten lines).

edit:

based on Trey Jackson's very wonderful work, here is my additional version:

(defvar my-m-x-log-file "~/mx.log")
(defadvice execute-extended-command
  (after log-execute-extended-command activate)
  (let ((logfile (find-file-noselect my-m-x-log-file)))
    (with-current-buffer logfile
      (goto-char (point-max))
      (insert (format "%s --- %s --- "
              (current-time-string)
               this-command))
      (where-is this-command t)
      (insert "\n"))))

This logs the timestamp, the command, and the keybindings, and does not obscure any echos from the m-x commands.

You will have to save the log file manually like you would any other emacs buffer, unlike Trey's version. There may be a compromise possible where the file is written to but there is no message echod to the minibuffer obscuring results of a command.

Answer 2

You can start with this elisp, which will simply add the commands you execute to a given log file. You can get fancier and do automatic tallying if you want. Or, you can occasionally just pipe the file through a sort|uniq -c.

(defvar my-m-x-log-file "~/mx.log")
(defadvice execute-extended-command (after log-execute-extended-command activate)
  (let ((logfile (find-file-noselect my-m-x-log-file)))
    (with-current-buffer logfile
      (goto-char (point-max))
      (insert (format "%s\n" this-command))
      (save-buffer))))

Answer 3

Edit: On re-reading I believe that I have answered the wrong question. You might have been better off asking this on Stack Overflow since the answer probably required hacking elisp.

C-h f function-name

will get you the documentation on function-name, including the current key-binding.

C-h k <key stroke>

will show the current function bound to any key stroke

C-h b

will list all active key binding