How to print to the stdout / stderr from an emacs graphical session?

Question

I'd like to print into the terminal that started emacs, instead of using Emacs message, whats the most convenient way to do this in emacs that uses the terminal?

(printf "some number %d some string %s" 1 "test")

Answer 1

This macro provides an equivilant to C's printf or Python's print:

(defmacro printf (fmt &rest args)
  `(princ (format ,fmt ,@args) #'external-debugging-output))

Or as a function:

(defun printf (&rest args)
  (princ (apply #'format args) #'external-debugging-output))