a4 is a dynamic terminal window manager. One of eight tiling layouts is dynamically applied to all visible terminals. The terminal windows are grouped by tags, making it easy to visually switch between contexts of work. a4 automatically runs in a persistent session from which you can detach and reconnect. Any number of named sessions can exist simultaneously. Color schemes are dynamically applied to each terminal window, based on the text in its titlebar, helping the user to visually identify terminals based on attributes such as hostname, userid, and any other text programmed to display in the titlebar.
Four of the eight layouts divide the screen into two areas, one for a zoomed window and the other for a stack of the remaining windows. These four layouts can be adjusted during use to expand or shrink the number of windows in the zoom area and the overall size of the zoom area. They are named for the location of the zoom area: zoom_left, zoom_right, zoom_top, and zoom_bottom. The other four layouts are fullscreen, grid, rows, and columns.
Each terminal window can be tagged with one or more tags. The user then selects which tag or tags to view, and all windows with those tags are arranged in the dynamic layout. The list of all tags is displayed on the left of the status bar. Tag names are user defined with the default being the numerals 1 through 9.
Terminal windows can be minimized to a bar at the bottom of the screen. A minimized terminal keeps its tags but stays out of the user's way until it is unminimized again. Terminal windows can be set to read-only status in order to prevent accidental typing or closing. Terminal windows can be added to a focus group in order to type the same input into all simultaneously. Minimized and read-only terminal windows are never typed into, even if they are included in the focus group.
Terminal color schemes are dynamically applied by comparing the text of the terminal's title with an ordered set of user-defined color rules.
a4 supports 24-bit truecolor and is configurable by editing an a4.ini file. It is a partial rewrite of dvtm, which in turn is a text-based implementation of dwm. a4 now incorporates the concepts of the abduco project for persistence and session management.
It is best to compile the code yourself, if possible. If you don't have that
capability on your system there are two installation scripts available in
releases that easily installs pre-compiled binaries for your machine
architecture (uname -m). One script, install.sh, installs a4 for all users
on your system and must be run with sudo or as root. The other,
install-local.sh, requires no elevated privileges and just installs a4 in
your own $HOME/.local/ directories.
# Option 1: Compile yourself
git clone git@github.com:rpmohn/a4.git
cd a4
make && sudo make install
# Option 2: Install pre-compiled binary for all users with sudo
curl -LO https://github.com/rpmohn/a4/releases/latest/download/install.sh
chmod 700 ./install.sh
sudo ./install.sh
# Option 3: Install pre-compiled binary for yourself
curl -fsSL https://github.com/rpmohn/a4/releases/latest/download/install-local.sh | bash
Copy mode (Ctrl-g e) opens the scrollback buffer and current screen contents
of the focused terminal in an editor. The editor is specified by the
copymode_editor setting in a4.ini, or the $EDITOR environment variable,
or defaults to vi. The editor receives two file path arguments: $1 is the
input file containing the terminal content, and $2 is an output file. Any
text written to $2 when the editor exits is saved to the a4 paste buffer and
placed on the system clipboard. (The $2 argument may be ignored.) Use Ctrl-g p to paste the buffer into the focused terminal.
A simple customization to use less::
copymode_editor = sh -c 'less "$1"' --A customization to use a fuzzy finder for quick selection to the paste buffer and system clipboard:
copymode_editor = sh -c 'cat "$1" | fzf --multi > "$2"' --There's a configuration error in the xterm-256color file installed by some Linux distros that causes the mouse to behave incorrectly by printing characters to the terminal. If you experience this problem, run the following command to put a local, patched copy of the file in place for your login account:
infocmp xterm-256color | sed -E 's/(kmous=\\E\[)</\1M/' | tic -o ~/.terminfo -See a4term.com for more documentation, including a copy of the manual page and default keyboard maps.