ANSI Escape Codes (opens in new tab)

Specifically, relevant primary and reputable sources might include the ECMA-48 standard[1] (supposedly identical to the withdrawn ANSI one), the manuals for the various DEC VT-series terminals[2], the XTerm documentation already mentioned here[3], the detailed description of the VT100 state machine including how it fills the holes in the ECMA/ANSI spec[4], and maybe some compatibility tables[5]. There’s also a lot of folk wisdom beyond that, apparently, but nobody seems to have really gathered it in a usable form.

There is a Terminals WG over at the XDG[6], but I don’t know if they have produced anything useful yet.

[1]: https://www.ecma-international.org/publications-and-standard... [2]: https://vt100.net/ [3]: https://invisible-island.net/xterm/ctlseqs/ctlseqs.html [4]: https://vt100.net/emu/dec_ansi_parser [5]: https://terminalguide.namepad.de/ [6]: https://gitlab.freedesktop.org/terminal-wg

(ETA: another commenter also recommends https://bjh21.me.uk/all-escapes/all-escapes.xhtml)

MS-DOSisms like the BIOS int 10h mode switch you mentioned in another comment are included, but so are things like (xterm) 256 color codes, TrueColor, and alternate screen switching, which IIRC were not a thing in ANSI.SYS. (The color thing I'm very sure because VGA text modes only supported 16 colors, the alternate screen mode is only a guess, it's very popular in unixy terminal emulators, but seems mostly useless for DOS.)

I'm pretty sure these lean towards the VT series of DEC terminals when not standard, not the DOS terminal.

These escape sequences were known as ANSI long before the invention of ANSI.SYS. I suspect the standardization may be for the syntax and not the specific commands.

I remember warez groups distributing .ans files as their brand. Also, TheDraw was the preeminent ansi tool back in the day.

The first version of .sigs that I ever encountered were on BBSes that allowed ANSI codes in posts. I'm not sure which BBS software it was, but on at least one it was common for people to create fairly elaborate animations, slash-spinners, character flourishes, and other backspace-driven sequences for their message signoffs.

I still play around with BBS's but I have to look stuff up - funny thing about this new post was the external link has an 'visited' property unlike most stuff that comes across my feed because apparently I've landed on this github page a few times in the recent past... useful information!

I has a load of fun when I discovered this too, but eventually realised that a good cli app has focus, sensible use of opts, a succinct -h, reliable exit codes and above all easily parsed output on stdout.

Would be cool if the console did bold, italics, underline, and, my favourite, overline.

Here's a good example in this printer manual: https://mpi.com.es/wp-content/uploads/2015/06/USER-GUIDE-IGP...

Search for both "vertical tab" and "VFU" (Vertical Format Unit). The "VFU" would accept commands to set the vertical tab stops to match whatever form you had. Say there was an address box that was 6 lines the top, a multi-line field 10 lines from the top, and an SSN field 15 lines from the top, and so on. You could program those tab stops and have a tractor feed of those forms loaded. Which would be easier programmatically than, for example, doing the math on how the length of text in some multi-line field in between those two would change the amount of line feeds you would need to send to land in the SSN field.

So, something like:

<vt> Enter the Address Stuff

<vt> Enter some amount of multiline text without having to calculate how many lines it filled

<vt> Now you're in the SSN field

Like how the horizontal tab is several horizontal cells of whitespace, the vertical tab is several vertical cells of whitespace.

I only recall seeing it used on line or dot matrix printers. You could scroll the paper down at the current cursor point (some how this was different from line feed, maybe some printers allowed the number of lines skipped to be configured).

Aside: it’s so nice seeing a pyproject.toml these days.

It looks like we may be able to forego setup.cfg soon too. https://stackoverflow.com/a/64151860

Or you can use curses (or ncurses, or any other terminal-independent library) like an adult, and not create yet another “works best in iTerm” application. We’ve been down this road before, and we settled on curses and similar libraries to be terminal-independent.

CTRL-V is a common "quote the next character" input command: it's specified by POSIX (https://pubs.opengroup.org/onlinepubs/9699919799.2018edition... https://pubs.opengroup.org/onlinepubs/9699919799.2018edition...) and it works in bash (in vi mode and emacs mode) and zsh

It also works with just the bare terminal line discipline in many flavours of unix: look at the 'lnext' control character in the output from 'stty' on Linux, macOS, or BSD (but not POSIX).

(however the equivalent in emacs itself is ctrl-Q, probably for bad reasons)

Here is a shell script to set and use colors. I added the truecolor functions just now.

    #!/bin/dash

    fg () ( printf '\033[38;2;%d;%d;%dm' "${1:-0}" "${2:-0}" "${3:-0}"; )
    bg () ( printf '\033[48;2;%d;%d;%dm' "${1:-0}" "${2:-0}" "${3:-0}"; )
    fg256 () ( printf '\033[38;5;%dm' "${1:-0}"; )
    bg256 () ( printf '\033[48;5;%dm' "${1:-0}"; )


    N='\033[' x=30

    for a in Bl R G Y B M C W  # Black Red Green Yellow Blue Magenta Cyan White
    do eval $a='$N'"'"$((   x))"m'" \
           b$a='$N'"'"$((60+x))"m'" \
        ${a}bg='$N'"'"$((10+x))"m'" \
       b${a}bg='$N'"'"$((70+x))"m'"   # bX=bright Xbg=background bXbg=brgt bgnd
             x=$((1+x)) 
    done

    N=$N'0m'

    printf "${B}${Gbg}This is blue on a green background.$N\n"

    fg 255
    bg 255 255 255

    printf "This is red on a white background.$N\n"

    x=0

    while [ $x -lt 256 ]
    do y=$((255-x))
       fg256 $x
       bg256 $y
       printf "%.3d $N" $x
       [ $(((1+x)%16)) -eq 0 ] && echo ''
       x=$((1+x))
    done

    echo ''

And xterm even supports DECDWL, DECDHL, and DECSWL.

I cringe when they call it ASCII art…