sourcehut-mirrors/chawan技術ドキュメント

Chawan is a TUI web (and (S)FTP, Gopher, Gemini, ...) browser with CSS, inline image and JavaScript support.

It uses its own small browser engine developed from scratch, which can nevertheless display many websites in a manner similar to major graphical browsers.

It can also be used as a terminal pager.

A Unix-like operating system (Linux, *BSD, Haiku, macOS, ...) is assumed. On Windows you have to use WSL.

1. Clone the Chawan repository:
   git clone https://git.sr.ht/~bptato/chawan && cd chawan
2. Install the Nim compiler: https://nim-lang.org/install.html
   • Please use 2.0.0 or newer, ideally 2.2.12. (nim -v displays your Nim compiler's version.) The 1.6 branch from 1.6.14 upwards may still work, but it isn't recommended unless you have no other choice.
   • If you are using a 32-bit system, you probably need 2.2 or newer. 2.0 may still work if you export CFLAGS=-fpermissive.
3. Install the following dependencies:
   • OpenSSL (or LibreSSL)
   • libssh2
   • brotli
   • pkg-config
   • GNU make (gmake on non-GNU systems)
   • Quick copy-paste for Debian: apt install libssh2-1-dev libssl-dev libbrotli-dev pkg-config make
4. Run make (without arguments).
5. Install using make install (e.g. sudo make install).

Then, try:

$ cha -V # open in visual mode for a list of default keybindings
$ cha example.org # open your favorite website directly from the shell
$ mancha cha # read the cha(1) man page using `mancha'

You can also install Chawan from packages maintained by volunteers. Known stable packages are:

• Alpine Linux: https://pkgs.alpinelinux.org/packages?name=chawan
• Arch Linux: https://archlinux.org/packages/extra/x86_64/chawan/
• Debian (testing): https://packages.debian.org/chawan
• FreeBSD: https://www.freshports.org/www/chawan/
• Gentoo (::guru overlay): https://codeberg.org/gentoo/guru/src/branch/master/www-client/chawan
• Guix: https://packages.guix.gnu.org/packages/chawan/
• Homebrew: https://formulae.brew.sh/formula/chawan
• NetBSD: https://pkgsrc.se/www/chawan
• NixOS: https://search.nixos.org/packages?show=chawan
• Slackware (SBo): https://slackbuilds.org/repository/15.0/network/chawan/
• Void Linux: https://voidlinux.org/packages/?arch=x86_64&q=chawan

Unstable packages (tip of the master branch):

• AUR: https://aur.archlinux.org/packages/chawan-git
• AppImage: https://git.lerch.org/lobo/chawan-appimage/
• Gentoo (::guru overlay, live ebuild): https://codeberg.org/gentoo/guru/src/branch/dev/www-client/chawan/chawan-9999.ebuild
• Homebrew (using --HEAD): https://formulae.brew.sh/formula/chawan

Each release also comes with static binaries. However, their dependencies can quickly get out of date, so installing a package or compiling Chawan yourself is preferable.

Currently implemented features are:

• multi-processing, incremental loading of documents
• HTML5 support with various encodings (UTF-8, Shift_JIS, GBK, ...), forms, cookies
• CSS-based layout engine: supports flow layout, table layout, flexbox layout, double-width characters (CJK)
• user-programmable keybindings (defaults are vi(m)-like), mouse support
• JavaScript support in documents (disabled by default)
• inline image support with Sixel or Kitty protocol (disabled by default; see doc/image.md on how to enable)
• supports several network protocols: HTTP(S), (S)FTP, Gopher, Gemini, Finger, Spartan
• markdown viewer (cha README.md), man page viewer (mancha)
• user-defined protocols and file formats
• syscall filter based sandboxing on FreeBSD, OpenBSD and Linux (through capsicum, pledge and seccomp-bpf)
• bookmarks, history

...with a lot more planned.

First, read the troubleshooting document. If it doesn't help, open a ticket. In doing so, please make sure your tickets are valid markdown, or they become unreadable on the web interface.

If you want to send plain text e-mails not formatted as markdown, use the mailing list instead. You can also open tickets on the Codeberg mirror.

Patches can be sent to the aforementioned mailing list, as Codeberg pull requests, or in private. Use whatever is the most convenient for you.

Please do not submit tickets or patches that were generated with artificial neural networks (directly, indirectly, fully, or partially). Such patches will be rejected.

Chawan's documentation is available as man pages (man cha) and as Markdown files.

• build/compilation options: doc/build.md
• cha man page: doc/cha.md
• mancha man page: doc/mancha.md
• configuration options: doc/config.md
• API description (for keybindings): doc/api.md
• mailcap: doc/mailcap.md
• mime.types: doc/mime.types.md
• local CGI: doc/cgi.md
• protocols: doc/protocols.md
• inline images: doc/image.md
• CSS: doc/css.md
• terminal compatibility: doc/terminal.md
• troubleshooting: doc/troubleshooting.md

If you're interested in modifying the code:

• architecture: doc/architecture.md
• style guide, debugging tips, etc.: doc/hacking.md
• guide for interfacing with JS: doc/jsguide.md

w3m has been the main inspiration for Chawan; although the two do not share code, the UI and feature set is similar.

Some mailcap extensions, together with the browsecap facility, were borrowed from its fork w3mmee.

Chawan is dedicated to the public domain. See the UNLICENSE file for details.

Chawan also includes and depends on several permissively licensed libraries. For further details, check the about:license page in Chawan, or read the same document here.