Smex is a M-x enhancement for Emacs. Built on top of Ido, it provides a convenient interface to your recently and most frequently used commands. And to all the other commands, too.

Jump to Changelog.

• Get Smex

  • Via Marmalade or MELPA.
  • Or manually download Smex and set-up your load path. (Find out more.)

• To auto-start Smex every time you open Emacs add these lines to your .emacs file:

    (require 'smex) ; Not needed if you use package.el
    (smex-initialize) ; Can be omitted. This might cause a (minimal) delay
                      ; when Smex is auto-initialized on its first run.
  

• Bind some keys:

    (global-set-key (kbd "M-x") 'smex)
    (global-set-key (kbd "M-X") 'smex-major-mode-commands)
    ;; This is your old M-x.
    (global-set-key (kbd "C-c C-c M-x") 'execute-extended-command)
  

• Run Smex. (Type M-x, if that's your key binding).

The commands are displayed in an Ido completion buffer, ordered by relevance. The 7 most recently executed commands come first, the rest are sorted by frequency of use, command length and in alphabetical order.

Ido completion in 10 seconds: Typing selects matching commands: e.g. 'lnmd' matches 'line-number-mode'. C-s/C-r switches to the next/previous match. Enter executes the selected command.

smex-major-mode-commands runs Smex, limited to commands that are relevant to the active major mode. Try it with Dired or Magit.

C-h f, while Smex is active, runs describe-function on the currently selected command.

M-. jumps to the definition of the selected command.

C-h w shows the key bindings for the selected command. (Via where-is.)

Before accepting user input, Smex checks for new command definitions and updates its caches accordingly. You can disable auto-updating and gain some slight speed improvements on older systems by setting smex-auto-update to nil.

To manually update Smex, call it a second time while it is already running.

Additionally, you can teach Smex to auto-update after Emacs has been idle for 60 seconds: Call (smex-auto-update); provide an integer argument for a custom time period in seconds.

smex-show-unbound-commands shows frequently used commands that have no key bindings.

Smex keeps a file to save its state betweens Emacs sessions. The default path is "~/.smex-items"; you can change it by setting the variable smex-save-file.

Set smex-history-length to change the number of recent commands that Smex keeps track of.

Set smex-prompt-string for a custom prompt.

• Use execute-extended-command for running commands. This breaks support for Emacs versions older than 24 and obviates the user option smex-key-advice-ignore-menu-bar. (The default Emacs behaviour is to not show menu bar bindings.)

  As a result of this change, the variable suggest-key-bindings is now honored when executing commands.

• Save command history in extended-command-history, like M-x.

• Improved tab completion in the Smex minibuffer
• Add compatibility with command-frequency

• Remove smex-detect-legacy-save-file. Only relevant (but a breaking change) when you rely on a long deprecated default value of smex-save-file.
• Ignore smex-save-file when it's empty instead of raising an error. Warn on invalid data in smex-save-file. Fixes [issue #23] (#23).

• Allow running where-is on the selected command.
• Fix compatibility with ido-ubiquitous.

• Add auto-initialization.
• Minor fixes.

Smex is my first venture into Elisp. I'd be glad to receive patches, comments and your considered criticism.

Have fun with Smex!