MisTTY is a terminal application for Emacs 29.1 and up that allows
editing prompts using Emacs commands, like in the shell command, but
in a full-featured, modern terminal.
Note
Terminal support is provided by alacritty,
with the help of an Emacs module. Without that module, MisTTY
falls back to using the more limited Emacs built-in terminal eterm.
To avoid that install the module with M-x mistty-install or M-x mistty-install-dwim. For more details, head over to
https://mistty.readthedocs.io/en/latest/usage.html#module-with-alacritty
M-x mistty creates a buffer with an interactive shell. See
launching
for details.
In that buffer you can move around freely and run any Emacs command
you want - until you press TAB and end up with the native completion
or notice the shell autosuggestions. With MisTTY you have access to
both Emacs and the shell commands and editing tools. Like comint,
MisTTY supports remote shells with
TRAMP.
Additionally, commands that take over the entire screen, such as
less or vi also work, temporarily taking over the terminal zone
and keyboard.
MisTTY works well with Bash and ZSH, but it is especially well suited to running Fish. With Fish, you get autosuggestion, completion in full colors, directory tracking with OSC7, and prompt detection with OSC133 out of the box. Other shells can be configured to support all that
Special configuration isn't absolutely needed, as MisTTY tries to support supports any command-line programs with a prompt in a reasonable way, like python or ipython.
It is, however, possible that a shell or prompt command confuses it, especially advanced ones. In such a case, please consider turning on OSC133 support in the command and filing a bug report.
MisTTY is known to work on Linux and MacOS.
As its core, MisTTY is a frontend to a terminal emulator. Terminal emulation is provided by alacritty library, which emulates xterm and has support for modern terminal extensions.
MisTTY goes beyond plain terminal emulation in Emacs to provide a convenient tools for command-line editing. It does its best to make as much of Emacs editing capabilities available while on a prompt.
This idea is similar to coterm, which offers the same switch between
full-screen and line mode.
eat also has a semi-char mode, which is the closest there is to
MisTTY. In that mode, Emacs movements commands are available. However,
Emacs commands that modify the buffer, aren't available to edit the
command line. In contrast, MisTTY allows Emacs to navigate to and edit
the whole buffer, then replays changes made to the command-line.
Other terminal emulators are available for Emacs, such as vterm and
ghostty, which do terminal emulation well, but don't offer the deep
integration with Emacs commands that MisTTY does.
The following is just a quick introduction. Read the full documentation at https://mistty.readthedocs.io/en/latest/
You can install MisTTY:
- from MELPA, by typing
M-x package-install mistty - from source, by executing
(package-vc-install "https://github.com/szermatt/mistty")
Once the package is installed, run M-x mistty-install-dwim to
install the module. Without it, MistTTY will be usable, but limited to
the Emacs built-in terminal emulator.
Type M-x mistty to launch a new shell buffer in MisTTY mode, then
use it as you would comint.
You'll quickly notice some differences. For example TAB completion working just like in a terminal instead of relying of Emacs completion.
The purple line on the left indicates the portion of the buffer that's a terminal. What you type in there gets sent to the program, usually a shell, and translated by that program. The rest of the buffer is normal, editable, text.
Commands that takes the whole screen such as less or vi take you
into fullscreen mode for the duration of that command and most keys -
except for C-c and C-x are sent to the terminal. You can still
access previous commands in the scrollback zone by typing C-c C-j.
If you ever get into a situation where a command needs you to press
keys normally sent to Emacs, press C-q <key>.
You can also temporarily switch to the fullscreen mode map using C-c C-k or switch to a special keyboard capture mode with C-c C-q that
send everything but C-g to the terminal.
You will very likely want to send some keys you use often directly
to the terminal. This is done by binding keys to mistty-send-key
in mistty-prompt-map. For example:
(Use-package mistty
:bind (("C-c s" . mistty)
;; bind here the shortcuts you'd like the
;; shell to handle instead of Emacs.
:map mistty-prompt-map
;; fish: directory history
("M-<up>" . mistty-send-key)
("M-<down>" . mistty-send-key)
("M-<left>" . mistty-send-key)
("M-<right>" . mistty-send-key)))Also, unless the shell you're using does it automatically, you might also need to configure your shell to send out directory tracking information. For more details, see Directory Tracking.
See also the documentation for more details on configuring MisTTY .
Please check the FAQ and, if that doesn't help, take the time to file a bug report.
See the Contributing section of the documentation.
MisTTY requires Emacs 29.1 or later.