widecharwidth VS DomTerm

>For example, iTerm2 considers the "rosette" emoji to have width 1

The reason for this is quite possibly that Unicode 9 changed the width for some codepoints (mostly emoji) from 1 to 2, and iTerm until very recently (don't know if it's released yet) defaulted to the Unicode 8 widths, with an opt-in escape sequence to change to Unicode 9.

>This approach comes from the wcwidth utility, and the comment at the top of the C source file provides further insight into the difficulties faced here.

That's link goes to Markus Kuhn's implementation from 2007. It supports Unicode 5, and is by now woefully out of date. You don't want to use it anymore.

Most terminals have their own definition, and the annoying part is that the client application and the terminal need to have theirs in sync or they get weird glitches when moving the cursor.

Shameless plug: Fish's solution is widecharwidth[0], which is a python script that parses the Unicode data files and generates a wcwidth for C++, Javascript and Rust. It's still a wcwidth, meaning that it has issues with joining code points, but it's at least a start. It's up-to-date with Unicode 14 and, unless they change the data format (again) should be easy to update to future Unicode releases.

It's public domain and used by at least fish and WezTerm.

[0]: https://github.com/ridiculousfish/widecharwidth

With fish we've made the experience that relying on libc isn't good enough.

Specifically in the case of connecting to a server that typically has an old libc with old unicode information, from a desktop that has a much newer system, or in case of ambiguous characters, where libc will just give you one width that might not match what the terminal actually renders (and they frequently have configuration options to change it!).

So we've made something we call widecharwidth (https://github.com/ridiculousfish/widecharwidth), which is a python script that parses the unicode datafiles (UnicodeData.txt, emoji-data.txt and friends) and generates a header you can #include.

And someone's opened a PR to mosh to integrate it: https://github.com/mobile-shell/mosh/pull/1143

Completion for program P should be written and maintained by the "owner" of program P - and installed with program P. This is of course difficult when there are many different "shells" that each have their own "language" for specifying completions. A multi-shell completion library can help with this problem.

To me it make sense that completion for program P should be handled by program P itself. That way, completions are unlikely to get out of sync with the application, and the completion handler can use the same option parser as the application. A way to do this is to use a special "hidden" switch to request completion.

Specifically the DomTerm terminal emulator (https://domterm.org) handles its own completions. Bash allows you to register a command that handles completions for some other command. The following tells bash that to handle completions for the domterm command it should call domterm with the magic "#complete-for-bash" option followed by the existing line and position.

    complete -o nospace -C 'domterm "#complete-for-bash" "$COMP_LINE" "$COMP_POINT"' domterm

Sixel has the one advantage of being mplemented in xterm and a modest number of other terminals. Otherwise, it's a pretty bad format: Inefficient. Unclear and inconsistently implemented specification. All images have to be a multiple fof 6 pixel rows, which may not align with either image height or character height.

Some terminal implement some other protocols, but attempts to specify a standard have failed. There are some tricky issues, such as: When does an image or part of an image get erased? Can you write text on top of an image and if so how are they aligned? What happens if you write an image on top of existing text? On top of an existing image? How does scrolling affect things? What happens to the image on window resize or zoom? Can you reliably update part of an image?

DomTerm (https://domterm.org) supports images in two ways:

If interested in enhanced terminals, please take a look at DomTerm (https://domterm.org). It too optionally uses Tauri/Wry, though it can also also Electron, Qt, or a plain web-browser. You can embed images and rich text among other feayrures. DomTerm also has builtin tmux-like panes+tabs (mouse-draggable), detachable sessions, and a powerful "view" (selection) mode.

bash-preexec.sh and shell-integration.bash are copied from another terminal called DomTerm (that also offers click to position cursor) into ~/.local/share/DomTerm. Those files can be found here.

For people using or considering Mosh or Eternal Terminal: I'd love if you could try DomTerm (https://domterm.org). Specifically DomTerm's support for stable remote connections - see https://domterm.org/Remoting-over-ssh.html .

DomTerm (https://domterm.org) isn't quite what you asked for: It only indirectly has a JavaScript console: Since its frontend is a browser engine, you can open up a JavaScript debugger.

DomTerm (https://domterm.org) attempts to provide similar possibilities as TermKit. However, it starts with the position that it should also (and perhaps first) be a fully-functional modern mostly-xterm-compatible terminal emulator. On top of that we add rich html text, images, logical structure, "shell integrayion", and more.

DomTerm - JavaScript, Electron, Qt - Web browser, Linux (+ others?)

DomTerm (https://domterm.org) uses the Golden Layout library (https://github.com/golden-layout/golden-layout). As far as I can tell, this does everything mentioned in the article. It also supports tabs, and you can also reposition terminal windows by dragging, neither of which I saw mentioned in the article. (I'm currently working on being able to drag between top-level windows. It sort-of-works, but only at the proof-of-concept level.)

Please try DomTerm (https://domterm.org). The 2.9.4 AppImage (https://github.com/PerBothner/DomTerm/releases/tag/2.9.4) should have the needed support for grapheme clusters and hopefully work on reasonably up-to-date Linux systems. Of course there are more recent fixes and improvements if you don't mind building from source.