termax

A minimal standalone terminal emulator in Rust: it opens its own window, runs your shell on a PTY, and draws the screen itself.

How it works

key events ──► gui (egui window) ──► pty master ──► shell (child on pty slave)
screen     ◄── gui draws the Grid ◄── vte::Parser ◄── pty master output

Every byte the shell emits is fed through a VT escape-sequence parser into an in-memory screen model (Grid): a 2D array of styled cells plus a cursor. The egui front end draws that grid each frame and encodes key presses (text, Ctrl-chars, arrows, ...) into the bytes a terminal sends. This split — I/O, screen model, renderer — is the same architecture Alacritty and WezTerm use, and the model stays renderer-agnostic: any front end only needs Grid::cells and Grid::cursor.

Layout

• src/main.rs — wiring: PTY setup (portable-pty), shell spawn, the reader thread that pumps PTY output through the parser into the grid.
• src/term.rs — Grid screen model and the vte::Perform implementation: printing, line discipline, cursor movement (CUP/CUU/CUD/...), erase (ED/EL), SGR colors (16/256/truecolor), alternate screen tracking, resize.
• src/gui.rs — the egui front end: grid rendering (styled runs, block cursor, xterm 256-color palette), key-to-bytes encoding, window-resize to PTY-resize propagation.

Usage

cargo run                 # open a termax window running your $SHELL
cargo run -- htop         # run a one-off command instead
cargo test                # unit tests for the screen model

Or build with cargo build --release and launch target/release/termax directly — from a file manager, a launcher, or another terminal.

Where to take it next

• Scrollback: keep rows pushed off the top of the grid instead of dropping them, plus mouse-wheel scrolling.
• Selection and clipboard copy (paste already works).
• A real font stack: a configurable monospace font with bold/italic faces and wide-glyph (CJK, emoji) handling.
• More escape sequences: insert/delete line (IL/DL), scroll regions (DECSTBM), cursor save/restore, OSC window title.
• A proper alternate screen: a second grid swapped in/out, restoring the primary screen on exit (vim/less currently draw into the same grid).