mtm: A C repository from equwal

Introduction

mtm is the Micro Terminal Multiplexer, a terminal multiplexer.

It has four major features/principles:

Simplicity

There are only a few commands, two of which are hardly ever used. There are no modes, no dozens of commands, no crazy feature list.

Compatibility

mtm emulates a classic ANSI text terminal. That means it should work out of the box on essentially all terminfo/termcap-based systems (even pretty old ones), without needing to install a new termcap entry.

Size

mtm is small. The entire project is around 1000 lines of code.

Stability

mtm is "finished" as it is now. You don't need to worry about it changing on you unexpectedly. The only changes that can happen at this point are:

Bug fixes.
Translation improvements.
Accessibility improvements.
Fixes to keep it working on modern OSes.

Community

Rob posts updates about mtm on Twitter at http://twitter.com/TheKingAdRob.

Installation

Installation and configuration is fairly simple:

You need ncursesw. If you want to support terminal resizing, ncursesw needs to be compiled with its internal SIGWINCH handler; this is true for most precompiled distributions. Other curses implementations might work, but have not been tested.
Edit the variables at the top of the Makefile if you need to (you probably don't).
If you want to change the default keybindings or other compile-time flags, copy config.def.h to config.h and edit the copy. Otherwise the build process will use the defaults.
Run:
```
make
```
or:
```
make CURSESLIB=curses
```
whichever works for you.
Run make install if desired.

Usage

Usage is simple:

mtm [-T NAME] [-t NAME] [-c KEY]

The -T flag tells mtm to assume a different kind of host terminal.

The -t flag tells mtm what terminal type to advertise itself as. Note that this doesn't change how mtm interprets control sequences; it simply controls what the TERM environment variable is set to.

The -c flag lets you specify a keyboard character to use as the "command prefix" for mtm when modified with control (see below). By default, this is g.

Once inside mtm, things pretty much work like any other terminal. However, mtm lets you split up the terminal into multiple virtual terminals.

At any given moment, exactly one virtual terminal is focused. It is to this terminal that keyboad input is sent. The focused terminal is indicated by the location of the cursor.

The following commands are recognized in mtm, when preceded by the command prefix (by default ctrl-g):

Up/Down/Left/Right Arrow: Focus the virtual terminal above/below/to the left of/to the right of the currently focused terminal.
o: Focus the previously-focused virtual terminal.
h / v: Split the focused virtual terminal in half horizontally/vertically, creating a new virtual terminal to the right/below. The new virtual terminal is focused.
w: Delete the focused virtual terminal. Some other nearby virtual terminal will become focused if there are any left. mtm will exit once all virtual terminals are closed. Virtual terminals will also close if the program started inside them exits.
l: Redraw the screen.
PgUp/PgDown/End: Scroll the screen back/forward half a screenful, or recenter the screen on the actual terminal.

That's it. There aren't dozens of commands, there are no modes, there's nothing else to learn.

(Note that these keybindings can be changed at compile time.)

Screenshots

mtm running three instances of tine

mtm running various other programs

mtm showing its compatibility

Compatibility

(Note that you only need to read this section if you're curious. mtm should just work out-of-the-box for you, thanks to the efforts of the various hackers over the years to make terminal-independence a reality.)

By default, mtm advertises itself as a screen-bce terminal. This is what GNU screen and tmux advertise themselves as, and is a well-known terminal type that has been in the default terminfo database for decades.

(Note that this should not be taken to imply that anyone involved in the GNU screen or tmux projects endorses or otherwise has anything to do with mtm, and vice-versa. Their work is excellent, though, and you should definitely check it out.)

The (optional!) mtm Terminal Types

mtm comes with a terminfo description file called mtm.ti. This file describes all of the features supported by mtm.

If you want to install this terminal type, use the tic compiler that comes with ncurses:

tic -s -x mtm.ti

or simply:

make install-terminfo

This will install the following terminal types:

mtm: This terminal type supports all of the features of mtm, but with the default 8 "ANSI" colors only.
mtm-256color: Note that mtm is not magic and cannot actually display more colors than the host terminal supports.
mtm-noutf: This terminal type supports everything the mtm terminal type does, but does not advertise UTF8 capability.

That command will compile and install the terminfo entry. After doing so, calling mtm with -t mtm:

mtm -t mtm

will instruct programs to use that terminfo entry. You can, of course, replace mtm with any of the other above terminal types.

Using these terminfo entries allows programs to use the full power of mtm's terminal emulation, but it is entirely optional. A primary design goal of mtm was for it to be completely usable on systems that didn't have the mtm terminfo entry installed. By default, mtm advertises itself as the widely-available screen-bce terminal type.

Copyright and License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.

equwal/mtm