(defun \<command-name> (\<args>) "\<documentation>" (interactive "\<template>") \<body>)
Um exemplo:
(defun this-line-to-top-of-window (line)
"Reposition line point is on to top of window.
With ARG, put point on line ARG."
(interactive "P")
(recenter (if (null line)
0
(prefix-numeric-value line))))
O comando interactivediz como ler os argumentos interativamente. Digite C-h f interactivepara maiores detalhes.