6 ms·

https://www.ecma-international.org/publications-and-standards/standards/ecma-48/ https://www.ecma-international.org/publications-and-standard...

hnlmorg 4y ago
Not all terminal emulators follow that completely. Most only include a subset and some include their own proprietary escape codes too (like iTerm and Terminology have codes for rendering images. tmux has an escape code for changing the session title). Then there's other specs not included in that doc even outside of the aforementioned proprietary codes. Like Sixel, conventions on non-POSIX terminals, etc. Also lets not forget the popular-but-not-standardised conventions like the hyperlink escape codes (which I personally think shouldn't exist in the first place....but that's another topic entirely). Even standard ASCII characters can differ from one platform to another. Backspace being a classic example: ISO 646 describe it as ^H whereas ASCII 1963 has it as ^? This mess of differing compatibilities is exactly why termcap is a thing. Being an author of a readline library, this is a topic quite close to my heart :)
- easrng 4y ago
  hTerm and also IIRC kitty have image-rendering escape sequences too.
  - hnlmorg 4y ago
    Not familiar with hTerm. Got a link to the project? Would be good to add support for that to my image rendering library: https://github.com/lmorg/murex/blob/c77b893a58a682735ad7502c1c8464a629f90515/config/defaults/profile_all.mx#L819 https://github.com/lmorg/murex/blob/c77b893a58a682735ad7502c...
    - easrng 4y ago
      Upstream: https://chromium.googlesource.com/apps/libapps/+/HEAD/hterm https://chromium.googlesource.com/apps/libapps/+/HEAD/hterm Fork used by iSH: https://github.com/ish-app/libapps/tree/master/hterm https://github.com/ish-app/libapps/tree/master/hterm I looked at the docs (https://github.com/ish-app/libapps/blob/master/hterm/doc/ControlSequences.md#osc1337-iterm2-sequences-osc-1337 https://github.com/ish-app/libapps/blob/master/hterm/doc/Con...) and it appears to use the same protocol as iTerm. Here's an implementation: https://github.com/ish-app/libapps/blob/master/hterm/etc/hterm-show-file.sh https://github.com/ish-app/libapps/blob/master/hterm/etc/hte...
      - hnlmorg 4y ago
        Thank you
- Annatar 4y ago
- hnlmorg 4y ago
  > > ^? is the code for the [DEL] or [DELETE] key on physical terminals, that's why it's an ASCII standard. > When the PC bucket keyboards came, IBM in their usual idiocy simply put the [BACKSPACE] key where the [DELETE] key normally is, and what's worse, they made it not only move back one space but delete too. Thus came the sadness of everlasting redefining of deletion to be ^H when using a PC bucket keyboard. Indeed. And to confuse things even further, the [DEL] key on IBM keyboards sends the following ANSI escape sequence: [27 91 51 126] So we now have 3 different standards for deleting characters (and that's before you start looking at the escape sequences for deleting rows, nor supporting vi and/or emacs/readline bindings).
duskwuff 4y ago
The relevant ECMA standards are full of crazy bullshit that, to the best of my knowledge, nobody has ever implemented in any hardware or software terminal, like control sequences to make lines of text run vertically (SPD), or to fully justify text (JFY), or to use a Fraktur font (SGR 20). They're also incomplete -- they go into very little detail explaining what various control sequences should do, especially in exceptional circumstances, and they don't discuss Unicode at all (as they haven't been updated since the early 1990s).
- jart 4y ago
  Hi I'm one of the people cited by the article. Fraktur is awesome. I implemented it in my terminal. https://github.com/jart/cosmopolitan/blob/c6bbca55e9f977e386f619d08b343268f7ca6544/tool/build/lib/pty.c#L266 https://github.com/jart/cosmopolitan/blob/c6bbca55e9f977e386... Now that unicode makes it easy, there's no excuse not to have fraktur!
  - duskwuff 4y ago
    Wow, okay, guess I can cross that one off my list of "ECMA-48 features nobody implements". There's still plenty left on that list, though -- including at least one escape sequence I'm fairly certain was included as a joke (SPQR).
    - deleted 4y ago
      [deleted]
    - chris37879 4y ago
      I can think of a use case or 2. Thermal printers (for those wanting old timey unix line printing interfaces) or e-ink displays in console mode.
      - duskwuff 4y ago
        The joke in SPQR is the name -- https://en.wikipedia.org/wiki/SPQR https://en.wikipedia.org/wiki/SPQR The functionality is legitimate (although I doubt anyone uses it), but the name is pure silliness -- much like the PowerPC "eieio" instruction.

hnlmorg 4y ago

Not all terminal emulators follow that completely. Most only include a subset and some include their own proprietary escape codes too (like iTerm and Terminology have codes for rendering images. tmux has an escape code for changing the session title). Then there's other specs not included in that doc even outside of the aforementioned proprietary codes. Like Sixel, conventions on non-POSIX terminals, etc. Also lets not forget the popular-but-not-standardised conventions like the hyperlink escape codes (which I personally think shouldn't exist in the first place....but that's another topic entirely). Even standard ASCII characters can differ from one platform to another. Backspace being a classic example: ISO 646 describe it as ^H whereas ASCII 1963 has it as ^? This mess of differing compatibilities is exactly why termcap is a thing. Being an author of a readline library, this is a topic quite close to my heart :)

easrng 4y ago
hTerm and also IIRC kitty have image-rendering escape sequences too.
- hnlmorg 4y ago
  Not familiar with hTerm. Got a link to the project? Would be good to add support for that to my image rendering library: https://github.com/lmorg/murex/blob/c77b893a58a682735ad7502c1c8464a629f90515/config/defaults/profile_all.mx#L819 https://github.com/lmorg/murex/blob/c77b893a58a682735ad7502c...
  - easrng 4y ago
    Upstream: https://chromium.googlesource.com/apps/libapps/+/HEAD/hterm https://chromium.googlesource.com/apps/libapps/+/HEAD/hterm Fork used by iSH: https://github.com/ish-app/libapps/tree/master/hterm https://github.com/ish-app/libapps/tree/master/hterm I looked at the docs (https://github.com/ish-app/libapps/blob/master/hterm/doc/ControlSequences.md#osc1337-iterm2-sequences-osc-1337 https://github.com/ish-app/libapps/blob/master/hterm/doc/Con...) and it appears to use the same protocol as iTerm. Here's an implementation: https://github.com/ish-app/libapps/blob/master/hterm/etc/hterm-show-file.sh https://github.com/ish-app/libapps/blob/master/hterm/etc/hte...
    - hnlmorg 4y ago
      Thank you
Annatar 4y ago
hnlmorg 4y ago
> > ^? is the code for the [DEL] or [DELETE] key on physical terminals, that's why it's an ASCII standard. > When the PC bucket keyboards came, IBM in their usual idiocy simply put the [BACKSPACE] key where the [DELETE] key normally is, and what's worse, they made it not only move back one space but delete too. Thus came the sadness of everlasting redefining of deletion to be ^H when using a PC bucket keyboard. Indeed. And to confuse things even further, the [DEL] key on IBM keyboards sends the following ANSI escape sequence: [27 91 51 126] So we now have 3 different standards for deleting characters (and that's before you start looking at the escape sequences for deleting rows, nor supporting vi and/or emacs/readline bindings).

duskwuff 4y ago

The relevant ECMA standards are full of crazy bullshit that, to the best of my knowledge, nobody has ever implemented in any hardware or software terminal, like control sequences to make lines of text run vertically (SPD), or to fully justify text (JFY), or to use a Fraktur font (SGR 20). They're also incomplete -- they go into very little detail explaining what various control sequences should do, especially in exceptional circumstances, and they don't discuss Unicode at all (as they haven't been updated since the early 1990s).

jart 4y ago
Hi I'm one of the people cited by the article. Fraktur is awesome. I implemented it in my terminal. https://github.com/jart/cosmopolitan/blob/c6bbca55e9f977e386f619d08b343268f7ca6544/tool/build/lib/pty.c#L266 https://github.com/jart/cosmopolitan/blob/c6bbca55e9f977e386... Now that unicode makes it easy, there's no excuse not to have fraktur!
- duskwuff 4y ago
  Wow, okay, guess I can cross that one off my list of "ECMA-48 features nobody implements". There's still plenty left on that list, though -- including at least one escape sequence I'm fairly certain was included as a joke (SPQR).
  - deleted 4y ago
    [deleted]
  - chris37879 4y ago
    I can think of a use case or 2. Thermal printers (for those wanting old timey unix line printing interfaces) or e-ink displays in console mode.
    - duskwuff 4y ago
      The joke in SPQR is the name -- https://en.wikipedia.org/wiki/SPQR https://en.wikipedia.org/wiki/SPQR The functionality is legitimate (although I doubt anyone uses it), but the name is pure silliness -- much like the PowerPC "eieio" instruction.