use emacs to control tmux

There are two main use cases for using emacs to control tmux session.

  1. Recording your command history in a markdown file.
  2. Bash programming

How it works

tmux has many subcommands to control tmux, one of is send-keys, for example,

tmux send-keys -t ! ls

It sends ls to the last active window. refer to tmux manual for detail about -t

It is not easy to send control characters, like return, tab etc. Fortunately with latest tmux 3.0a, it supports -H command line option, e.g.

tmux send-keys -t ! -H 6c 73 0a

0a means return key so that we can execute ls in the last active window.

In elisp, we can easily convert any string into hex format as below

(defun tmux-cc--convert-keys(strings)
  (seq-map #'(lambda(c) (format "%x" c)) strings))

(tmux-cc--convert-keys "ls\n") => ("6c" "73" "a")

It becomes interesting when we invoke tmux send-keys from within a emacs session.

(setq strings "ls\n")
(apply #'call-process
   `("tmux" nil "*tmux cc*" t
     "send-keys" "-t" "op" "-H" ,@(tmux-cc--convert-keys strings)))

In this way, we can send arbitrary strings from a emacs buffer to a tmux session.

There is a complete implemenation in https://github.com/wcy123/tmux-cc

To install the package, you can put the following lines in your ~/.emacs.

(use-package tmux-cc
  :straight
  (tmux-cc :type git
           :host github
           :repo "wcy123/tmux-cc")
  :commands
  (tmux-cc-send-current-line tmux-cc-select-block tmux-cc-send-region))

And it is recommended to bind C-z in markdown-mode or shell-script-mode.

(use-package markdown-mode
  :defines (markdown-mode-map)
  :mode "\\.md\\'"
  :mode "\\.markdown\\'"
              ("C-z" . tmux-cc-send-current-line))

Or you can just install https://github.com/wcy123/100ms_dot_emacs it works out of box.