(command-line-1): Add option --eval to evalute an

expression on the command line and print the result.

diff --git a/lisp/startup.el b/lisp/startup.el
index 42a3a5c576f78cb43a555b62c332ed29bc097e0a..b482aa880def84bf23dddef4f6e8884f9f5e4d96 100644 (file)
--- a/lisp/startup.el
+++ b/lisp/startup.el
@@ -101,6 +101,9 @@
 ;; --funcall FUNC            and should not be used.  (It's a typo
 ;; -e FUNC                   promoted to a feature.)
 ;;
+;; -eval FORM                Execute Emacs lisp form FORM, and print
+;; --eval FORM               the value it returns.
+;;
 ;; -insert FILE              Insert the contents of FILE into buffer.
 ;; --insert FILE
 ;; -------------------------
@@ -674,7 +677,7 @@ Type \\[describe-distribution] for information on getting the latest version."))
               ;; and long versions of what's on command-switch-alist.
               (longopts
                (append '(("--funcall") ("--load") ("--insert") ("--kill")
-                         ("--directory"))
+                         ("--directory") ("--eval"))
                        (mapcar '(lambda (elt)
                                   (list (concat "-" (car elt))))
                                command-switch-alist)))
@@ -717,6 +720,12 @@ Type \\[describe-distribution] for information on getting the latest version."))
                 (if (arrayp (symbol-function tem))
                     (command-execute tem)
                   (funcall tem)))
+               ((string-equal argi "-eval")
+                (if argval
+                    (setq tem argval)
+                  (setq tem (car command-line-args-left))
+                  (setq command-line-args-left (cdr command-line-args-left)))
+                (print (eval (read tem))))
                ;; Set the default directory as specified in -L.
                ((or (string-equal argi "-L")
                     (string-equal argi "-directory"))