# avt - asciinema virtual terminal

avt is asciinema's implementation of virtual terminal emulator written in Rust.

It is used by [asciinema CLI](https://github.com/asciinema/asciinema),
[asciinema player](https://github.com/asciinema/asciinema-player), [asciinema
server](https://github.com/asciinema/asciinema-server) and [asciinema gif
generator](https://github.com/asciinema/agg).

This implementation covers only parsing and virtual buffer related aspects of a
terminal emulator as it's all asciinema needs.

avt consists of:

- parser for ANSI-compatible video terminal based on [excellent state diagram by Paul Williams](https://www.vt100.net/emu/dec_ansi_parser),
- virtual screen buffers (primary/alternate) in a form of character grid with additional color/styling attributes,
- API for feeding text into the parser and for querying virtual screen buffer and cursor position.

Following aspects of terminal emulation are not in scope of this project:

- input handling,
- rendering.

While avt is small and focused, a full-fledged terminal emulator could potentially be
built on top of it.

avt doesn't try to 100% replicate any specific terminal variant like VT102 or VT520,
instead it implements most control sequences supported by modern terminal emulators
like xterm, Gnome Terminal, WezTerm, Alacritty, iTerm, mosh etc.

## License

© 2019 Marcin Kulik.

All code is licensed under the Apache License, Version 2.0. See LICENSE file for details.