Function: describe-function

describe-function is an autoloaded, interactive and byte-compiled function defined in help-fns.el.gz.

Signature

(describe-function FUNCTION)

Documentation

Display the full documentation of FUNCTION (a symbol).

When called from Lisp, FUNCTION may also be a function object.

See the help-enable-symbol-autoload variable for special handling of autoloaded functions.

View in manual

Probably introduced at or before Emacs version 22.1.

Key Bindings

Source Code

;; Defined in /usr/src/emacs/lisp/help-fns.el.gz
;;;###autoload
(defun describe-function (function)
  "Display the full documentation of FUNCTION (a symbol).
When called from Lisp, FUNCTION may also be a function object.

See the `help-enable-symbol-autoload' variable for special
handling of autoloaded functions."
  (interactive (help-fns--describe-function-or-command-prompt))

  ;; We save describe-function-orig-buffer on the help xref stack, so
  ;; it is restored by the back/forward buttons.  'help-buffer'
  ;; expects (current-buffer) to be a help buffer when processing
  ;; those buttons, so we can't change the current buffer before
  ;; calling that.
  (let ((describe-function-orig-buffer
         (or describe-function-orig-buffer
             (current-buffer)))
        (help-buffer-under-preparation t))

    (help-setup-xref (list #'describe-function--helper
                           function describe-function-orig-buffer)
                     (called-interactively-p 'interactive))

    (save-excursion
      (with-help-window (help-buffer)
        (if (get function 'reader-construct)
            (princ function)
          (prin1 function))
        ;; Use " is " instead of a colon so that
        ;; it is easier to get out the function name using forward-sexp.
        (princ " is ")
        (describe-function-1 function)
        (with-current-buffer standard-output
          ;; Return the text we displayed.
          (buffer-string))))))