smtx -- Simple Modal Terminal Multiplexer

Designed for simplicity and ease of use in a limited environment (eg, on a small physical device), smtx provides provides ptys that are wider than the physical device and the ability to have multiple views in different locations of the pty.

https://terminalizer.com/view/28083a105080 https://terminalizer.com/view/e38467005081

When first started, smtx creates a single window with a pty running the program specified in SHELL. The window that is created will fill the physical screen, and the underlying pty that it is viewing will have a width of at least 80. The CMD keysequence (default is CTRL g) will put smtx in command mode in which key sequences are interpreted to manipulate the windows. Press RETURN to exit command mode. Press CMD to exit command mode and send CMD to the underlying pty. In command mode, create new windows using c or C. Use hjkl to navigate between windows. Use < and > to horizontally scroll the underlying pty. Most commands accept a count, so you could create 5 new windows with 5c and move down N times with Nj. (In the follwoing, N will represent an arbitrary integer). Choose one of the preset layouts with Nv. To attach a different pty to the current window, use Na. To swap the pty in the current window with the pty in a different window, use NS. To move the focus to the window with pty N, use Ng. To transpose the orientation of the current window, use T. To close the currently focused window (the underlying pty is not affected), use x. To destroy all of the ptys and exit, use 0x.

smtx is modal, so you can enter multiple commands from command mode without typing the CMD keysequence multiple times. From command mode, you can create 5 new windows with ccccc, or 5c. There are several preset layouts, so you can get a layout of 5 windows with 5v. You can recursively convert an axial split to a sagittal split with T (transpose), and you can discard the currently focused window and all its children with x. To attach the current window to a different pty, use a. To swap the pty of the current window with a pty in a different window, use s. Change the width of the pty in the currectly focused window with W.

You can also generate a window layout with an osc sequence. To generate a layout with seven windows, you could do:

printf '\033]60;.5:.5 .25:.66 .5:.66 .5:.83 .5:1 1:.25 1:1\007'

where each coordinate pair represents the lower right hand corner of the window as a fraction of the full screen (note that order matters).

New windows are created in command mode with create, which is by default bound to the keystrokes c and C. To navigate among the windows use j, k, l, and h. The navigation is not directly related to the physical layout on the screen, but navigates the tree structure of the extant windows. Each window belongs to one "canvas", which is simply a node in the tree used to keep track of windows. The root canvas fills the entire physical screen and contains the window in the upper left. Each canvas can have 0, 1, or 2 children. If the root window is split on the axial plane (ie, split top to bottom), the root canvas is said to be of "type 0" and has one child. If the root window is split on the sagittal plane (ie, split left to right), the root canvas is of "type 1". That is, a layout with 3 windows in which the left half of the screen is full height and the right half of the screen is split into 2 half-height windows indicates a root canvas of type 1. In that layout, the root canvas has one child (the right half of the screen), and that child (which is a type 0 canvas) has one child. The window navigation follows this tree structure naturally. h and l move the cursor to the left and right child of the currently focused canvas. k moves to the parent canvas, and j moves to the primary child; left for type 0, and right for type 1.

Usage is simple:

smtx [-c ctrl-key] [-s history-size] [-t terminal-type] [-v] [-w width]

The -t flag tells smtx what terminal type to advertise itself as. (This just 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 smtx when modified with control (see below). By default, this is g.

The -s flag controls the amount of scrollback saved for each terminal.

The -w flag sets the minimum width for newly created ptys (default is 80).

Ths -v flag causes smtx to print its version and exit.

Once inside smtx, things pretty much work like any other terminal. However, smtx 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 smtx when in command mode:

h/j/k/l/Up/Down/Left/Right Arrow

Move the focus to the virtual terminal in the window of the canvas that is the child/parent of the currently focused terminal.

c / C

Split the focused virtual terminal in half horizontally/vertically, creating a new virtual terminal to the right/below. The old virtual terminal retains the focus.

b/f

Scroll the screen back/forward half a screenful, or recenter the screen on the actual terminal.

-/|

Change the size of the current window to be the specifiec percentage of the enclosing canvas. eg, '25|' will make the current window use 25% of the horizontal space of the canvas.

= Recursively rebalance windows. By itself, rebalance in both

directions. 1= and 2= will rebalance only horizontally or vertically, respectively.

W

Set the width of the focused pty. eg, to set the width of the currently focused pty to 120, enter command mode and type 120W

[0-9] Set a command count.

(Note that these keybindings can be changed at compile time, and that the above list is incomplete and subject to change.)

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

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

tic -s -x smtx.ti

Using these terminfo entries allows programs to use the full power of smtx's terminal emulation, but it is entirely optional. If the terminfo file is not installed, smtx will use reasonable defaults.

Copyright 2016-2019 Rob King <[email protected]>

Copyright 2020-2023 William Pursell <[email protected]>

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/>.