BiDirectional Text

BiDiSupport.md

This gist will show the support of BiDirectional text in the terminal emulators and console programs. You can read more about the standardization efforts at the dedicated page of FreeDesktop Terminal BiDi working group.

How to test

Logical Order	◀ ◀ ◀ RTL	LTR ▶ ▶ ▶
WHAT IS UNICODE؟ in arabic	in arabic ؟EDOCINU SI TAHW	؟EDOCINU SI TAHW in arabic
	ما هو الترميز الموحد يونيكود؟ in Arabic	ما هو الترميز الموحد يونيكود؟ in Arabic

Supporting BiDirectional text

According to a new standard

Please note, that specification is preliminary yet, and VTE implementation is still work in progress:

• all libvte based terminals - https://gitlab.gnome.org/GNOME/vte/issues/53
  • libvte-based Gnome Terminal - https://bugs.launchpad.net/ubuntu/+source/vte/+bug/263822
  • libvte-based sakura
  • libvte-based xfce4-terminal
  • libvte-based Terminator
  • libvte-based Tilix - written in D. Similar user interface as for Terminator.
  • libvte-based Lilyterm - https://github.com/Tetralet/LilyTerm/
  • libvte-based ROXTerm
  • libvte-based evilvte https://github.com/caleb-/evilvte
  • libvte-based Termit
  • libvte-based Tilda
  • libvte-based tinyterm
  • libvte-based Pantheon Terminal
  • libvte-based lxterminal

Incompatible and incomplete implementations

• mlterm
• konsole
• qterminal
• mintty Cygwin and MSYS/MSYS2 - Windows platform

Supporting BiDirectional text programs, but incompatible

• neatvi - Vi-like editor aligrudi/neatvi#8

Not supporting BiDirectional text

• another libvte-based Termite
• st (from suckless)
• xst fork of st gnotclub/xst#55
• iterm2
• alacritty - written in Rust alacritty/alacritty#663
• kitty - uses OpenGL kovidgoyal/kitty#2109
• cool-retro-term
• Termux - Android platform
• Black Screen - crossplatform, HTML/CSS/JS-based
• Hyper.app - crossplatform, HTML/CSS/JS-based (Electron)
• hterm - HTML/CSS/JS-based (ChromeOS)
• Windows Terminal - Windows platform, standard terminal microsoft/terminal#538
• Tera Term - Windows platform
• ConEmu - Windows platform Maximus5/ConEmu#1665
• FinalTerm - abandoned, iTerm2 borrowing it's ideas and features.
• MacTerm - Mac OS X platform
• Windows 10 bash and cmd.exe console - https://wpdev.uservoice.com/forums/266908-command-prompt-console-windows-subsystem-for-l/suggestions/34937857-bidirectional-text-support

Terminal multiplexers

• tmux - not yet tmux/tmux#1936
• screen - not yet
• pymux - not yet prompt-toolkit/pymux#77
• dvtm - not yet martanne/dvtm#99

Not supporting BiDirectional text programs

• neovim - neovim/neovim#553
• vim - vim/vim#204
• radare2 - https://github.com/radare/radare2/issues/2032
• irssi - irssi/irssi#1133

I'd say all terminals I've seen to do bidi do it that way - how else? To check, however, please upload your test file.

The konsole feature "Table characters BiDi mode override" might be interesting but unfortunately it is not really specified (which characters? examples?); maybe I'll submit them an issue.

@wolandark

In any VTE-based terminal, echo '\e[?2501h' to enable auto-direction, and you should get the same behavior.

This comes from terminal-wg's BiDI draft proposal.

@MoSal Neat! I didn't know that. After running the escape sequence, XFCE terminal also behaves the same as Konsole does.

@mintty here is a sample of the text (though what I shared in the screenshot was being fetched from an API).

As mentioned above, doing as MoSal suggested, makes XFCE terminal (which is VTE) behave the same way as Konsole, so I guess my defense of Konsole is relevant, though in my defense there is no need to run any escape sequence in Konsole to get this behavior.

though in my defense there is no need to run any escape sequence in Konsole to get this behavior.

FWIW, LTR instead of AUTO as a default paragraph direction was a design choice which I, as a native speaker of an RTL language, tend to agree with.

The konsole feature "Table characters BiDi mode override" might be interesting

It appears that mintty already has a mode that seems to render table layout like konsole: echo -e "\e[?2501l".