Emacs: How to Evaluate Emacs Lisp Code

Xah Lee, 2007-12-30, …, 2011-11-05

This page shows you how to evaluate emacs lisp code.

To evaluate a single lisp expression, move your cursor to the right of the last closing parenthesis, and call eval-last-sexp 【Ctrl+x Ctrl+e】.

To evaluate a text selection, call eval-region.

Here's a list of other ways, roughly in order of usefulness:

Command Name	Acting Area	Key
`eval-last-sexp`	the complete lisp expression to the left of cursor	【`Ctrl`+`x` `Ctrl`+`e`】
`eval-defun`	the function definition block (defun) the cursor is in. (your cursor needs to be near top level.)	【`Ctrl`+`Alt`+`x`】 (only when in lisp modes)
`eval-region`	text selection	◇
`eval-buffer`	whole file in current window	◇
`load-file`	promps you for a file name	◇
`eval-expression`	promps you to type code	◇

For commands that do not have a key, you can assign them a key, or you can give them a alias for convenience, e.g. “eb” for eval-buffer.

Also, emacs has a interactive emacs lisp shell: 【Alt+x ielm】. You might find it useful. I never liked programing in a shell interface, so i never used ielm. I prefer a notebook-style interface, i always code elisp in a new empty file.