Notes

[PedroRegisPOAR]

Abstract

There are 4 packages in nixpkgs involved, at least.

nix build nixpkgs#glibcLocales

nix build nixpkgs#glibc.bin

nix build nixpkgs#locale

nix build nixpkgs#glibc

Some notes about locale/locale-archive

• domenkozar opened this issue on Mar 18, 2015 · 15 comments: document locale issues NixOS/nixpkgs#6878
• trofi opened this issue on Jan 11, 2017 · 10 comments: nix-shell --pure: non-POSIX locales do not work (by default) NixOS/nixpkgs#21820
• [bisected] Locale broken with nixpkgs on Fedora {29…31} NixOS/nixpkgs#60414
• LOCALE_ARCHIVE is unconfigurable and unconditional nix-community/home-manager#2333
• https://stackoverflow.com/questions/5909404/sort-not-sorting-as-expected-space-and-locale/5909526#5909526
• https://stackoverflow.com/questions/23660247/treatment-of-spaces-in-sort-command-difference-between-lc-collate-c-and-lc-coll?rq=1
• https://mpickering.github.io/posts/2018-09-19-nix-artefacts.html "LOCALE_ARCHIVE=${glibcLocales}/lib/locale/locale-archive"

Old, but really great: NixOS/nix#599 (comment)

TODO: take a look in this, lots of troubleshoot commands:
NixOS/nix#599

What is the locale-archive

locale-archive is a memory-mapped file which is generated by locale-gen(8) invoking localedef(1). Memory-mapped means that once it is created and called by a program it is only loaded once into memory.
https://unix.stackexchange.com/a/331706

Difference between locale-archive and Machine Object files in /usr/share/locale/<locale_dir>/LC_MESSAGES/ directory?

TODO: add real updated values and sha256sum

In the above case deleting all locales except the en_* ones my locale-archive went from 102MB down to 3.4MB
https://unix.stackexchange.com/a/498523

find . ! -name 'file.txt' -type f -exec rm -f {} +
From: https://unix.stackexchange.com/a/153863

glibc

glibc = super.glibc.overrideAttrs (_: {
      # Warning: MASSIVE rebuild since you'll break ABI
      version = "2.26";
    });

From: https://gurkan.in/wiki/nix.html#override-example-optional-args

TODO: convert this to a flake nix-shell cannot change locale warning

Some troubleshoot commands:

• strace -e file locale
• ls /usr/share/i18n/charmaps/
• gzip -dk UTF-8.gz
  From: Locale issue after upgrading to Ubuntu 16.10 from a clean installation of Ubuntu 16.04

Saving all this for now:

• setlocale() fails for anything other than "C" (missing locale-archive?)
• glibc 2.27 breaks locale support
• Make NixOS provide version-specific LOCALE_ARCHIVE environment variables
• glibc 2.27 breaks locale support
• Change the order of locale archive search path
• A function to build Glibc's locale-archive separately from Glibc.
• Imperative packagement replacement in nixFlakes aka nix profile NixOS/nix#3579 (comment)
• https://askubuntu.com/a/1028473
• Document how to work around dynamic linking problems caused by glibc updates NixOS/nixpkgs#170897

I think the proper fix would be to include en_US.utf-8 in our glibc version by default (can be done via overrideAttrs) and rebuild python/bash/perl against that.
Build a yocto rootfs inside nix

Force install locale from "glibcLocales" since there are collisions
extraBuildCommands = ''
ln -sf ${glibcLocales}/lib/locale/locale-archive $out/usr/lib/locale
'';
stammw/yocto.nix

After evaluating this issue, there are no plans to address it further or fix it in an upcoming release. Therefore, it is being closed. If plans change such that this issue will be fixed in an upcoming release, then the bug can be reopened.
Unable to invoke localedef to UTF-8: cannot read character map directory `/usr/share/i18n/charmaps'

TODO: https://unix.stackexchange.com/questions/187402/nix-package-manager-perl-warning-setting-locale-failed/243189#243189

Maybe useful:
https://github.com/davidtwco/veritas/blob/6f2c676a76ef2885c9102aeaea874c361dbcaf61/home/profiles/common.nix#L197-L198

TODO: document from where it came from, the python PEPs about it

nix run nixpkgs#python3 -- <<<'print("ℙƴ☂ℌøἤ")'

• https://peps.python.org/pep-0538/
• https://peps.python.org/pep-0540/

At the moment, setting "LANG=C" on a Linux system fundamentally breaks Python 3, and that's not OK.
ENV LANG C.UTF-8
https://github.com/docker-library/python/blob/56cea612ab370f3d05b29e97466d418a0f07e463/3.10/slim-bullseye/Dockerfile#L12-L14

https://click.palletsprojects.com/en/5.x/python3/#python-3-surrogate-handling

[PedroRegisPOAR]

Abstract

To explain, the default glibc package doesn't contain locale data – that's separate and --pure isn't supposed to see OS data.
Source: NixOS/nixpkgs#32848 (comment)

Adding glibcLocales to the shell indeed fixes the issue. Though this raises the question
as to whether that dependency needs to be explicitly added to any package that depends
on glibc and does some kind of text processing. Locales are a non-optional part of the C
standard and while it’s great to be able to drop the heavyweight dependency where you
know it’s irrelevant, it should not be absent in the default context.
From:

• [bisected] Locale broken with nixpkgs on Fedora {29…31} NixOS/nixpkgs#60414 (comment)

MWE

MWE 1:

LC_ALL=en_GB.utf8 date '+%c'
LC_ALL=en_US.utf8 date '+%c' 

nix \
run \
nixpkgs#python39 \
-- \
-c \
'
import locale
locale.setlocale(locale.LC_ALL, "pt_BR.utf8")
print(locale.currency(12345.67, grouping=True, symbol=True))
'

copy/pastes

Code 1:

# 
# nix flake metadata nixpkgs --json | jq -r .url
nix \
store \
ls \
--store https://cache.nixos.org/ \
--long \
--recursive \
"$(nix eval --raw github:NixOS/nixpkgs/9eb60f25aff0d2218c848dd4574a0ab5e296cabe#glibcLocales)"

Code 2:

# 
# nix flake metadata nixpkgs --json | jq -r .url
nix \
store \
ls \
--store https://cache.nixos.org/ \
--long \
--recursive \
"$(nix eval --raw github:NixOS/nixpkgs/9eb60f25aff0d2218c848dd4574a0ab5e296cabe#glibc)"

Code 3:

# 
# nix flake metadata nixpkgs --json | jq -r .url
nix \
store \
ls \
--store https://cache.nixos.org/ \
--long \
--recursive \
"$(nix eval --raw github:NixOS/nixpkgs/9eb60f25aff0d2218c848dd4574a0ab5e296cabe#locale)"

Code 4:

# 
# nix flake metadata nixpkgs --json | jq -r .url
nix \
store \
ls \
--store https://cache.nixos.org/ \
--long \
--recursive \
"$(nix eval --raw github:NixOS/nixpkgs/9eb60f25aff0d2218c848dd4574a0ab5e296cabe#glibc.bin)"

# nix flake metadata github:NixOS/nixpkgs/release-22.05 --json
command -v jq >/dev/null || nix profile install github:NixOS/nixpkgs/4aceab3cadf9fef6f70b9f6a9df964218650db0a#jq \
&& nix \
build \
--impure \
--expr \
'(
  with builtins.getFlake "nixpkgs";
  with legacyPackages.${builtins.currentSystem};
  (
    glibcLocales.override {
        allLocales = false;
        locales = [ 
                           "en_GB.UTF-8/UTF-8" 
                           "ru_RU.UTF-8/UTF-8" 
                           "en_US.UTF-8/UTF-8" 
                           "pt_BR.UTF-8/UTF-8"
                           "ja_JP.UTF-8/UTF-8"
                           "en_IE.UTF-8/UTF-8"
                     ];
      }
  )
)'

Refs.:

• fetchzip: force UTF-8 compatible locale to unpack non-ASCII symbols NixOS/nixpkgs#176253 (comment)
• https://unix.stackexchange.com/a/62317

LOCALE_ARCHIVE=result/lib/locale/locale-archive \
&& LC_ALL=pt_BT.UTF-8 \
&& nix \
run \
nixpkgs#python39 \
-- \
-c \
'
import locale

locale.setlocale(locale.LC_ALL, "pt_BR.utf8")
print(locale.currency(12345.67, grouping=True, symbol=True))

locale.setlocale(locale.LC_ALL, "en_US.utf8")
print(locale.currency(12345.67, grouping=True, symbol=True))

locale.setlocale(locale.LC_ALL, "ru_RU.utf8")
print(locale.currency(12345.67, grouping=True, symbol=True))

locale.setlocale(locale.LC_ALL, "ja_JP.utf8")
print(locale.currency(12345.67, grouping=True, symbol=True))

locale.setlocale(locale.LC_ALL, "en_IE.utf8")
print(locale.currency(12345.67, grouping=True, symbol=True))
'

{ cat <<WRAP >> foo.c
#include <stdio.h>
#include <locale.h>

int main()
{
    char *locale = setlocale(LC_ALL, "");
    printf("\n locale =%s\n", locale);
    printf("test\n \u263a\u263b Hello from C\n");

    return 0;
}
WRAP
} && gcc foo.c \
&& ./a.out

rm -f a.out foo.c

Refs.:

• https://stackoverflow.com/a/58071375

TODO:

nix run nixpkgs#gcc -- -xc -E -v /dev/null

printf '#include <locale.h>\nLC_COLLATE\n' | gcc -E -x c - | tail -n 1

Refs.:

• https://unix.stackexchange.com/a/449236

nix run nixpkgs#python39 -- -c "assert '\N{snake}' == '🐍'"

TODO:

printf %b\\n \\u04{51,{3,4}{{0..9},{a..f}}}|sort|sed 's/./\u&&/'|tr -d \\n

Refs.:

• https://codegolf.stackexchange.com/a/127708

cowsay

nix \
shell \
--ignore-environment \
--impure \
--expr \
'
  (
    let
      nixpkgs = (builtins.getFlake "github:NixOS/nixpkgs/0938d73bb143f4ae037143572f11f4338c7b2d1c");
      pkgs = import nixpkgs { };    
    in
      with pkgs; [
        cowsay
      ]
    )
' \
--command cowsay "Hello"

nix \
shell \
--ignore-environment \
--impure \
--expr \
'
  (
    let
      nixpkgs = (builtins.getFlake "github:NixOS/nixpkgs/0938d73bb143f4ae037143572f11f4338c7b2d1c");
      pkgs = import nixpkgs { };    
    in
      with pkgs; [
        (
          glibcLocales.override {
              allLocales = false;
              locales = [
                          "en_US.UTF-8/UTF-8" 
                          "pt_BR.UTF-8/UTF-8"
                        ];
            }
        )
        cowsay
      ]
    )
' \
--command cowsay "Hello"

Refs.:

• Matthew Croughan - What Nix Can Do (Docker Can't) - SCaLE 20x, start=4388&end=4402

Others

LOCALE_ARCHIVE=result/lib/locale/locale-archive


LC_ALL=pt_BR.UTF-8 date '+%c'
LC_ALL=en_US.UTF-8 date '+%c'
LC_ALL=ru_RU.UTF-8 date '+%c'
LC_ALL=ja_JP.UTF-8 date '+%c'
LC_ALL=en_IE.UTF-8 date '+%c'

LOCALE_ARCHIVE=result/lib/locale/locale-archive


LC_ALL=en_GB.UTF-8
nix run nixpkgs#uutils-coreutils -- date '+%c'


LC_ALL=en_US.UTF-8
nix run nixpkgs#uutils-coreutils -- date '+%c'

LOCALE_ARCHIVE=result/lib/locale/locale-archive


LC_ALL=en_GB.UTF-8
nix run nixpkgs#busybox -- date '+%c'


LC_ALL=en_US.UTF-8
nix run nixpkgs#busybox -- date '+%c'

nix \
run \
nixpkgs#python39 -- \
-c \
"
v=32
while v:print('Ёё'*(v==26),end='%c%c'%(1072-v,1104-v));v-=1
"

export LC_ALL=en_US.utf8
nix run nixpkgs#python39 -- -c '
import locale
defaultlocale = locale.getdefaultlocale()
locale.setlocale(locale.LC_ALL, defaultlocale[0] + "." + defaultlocale[1])
print(locale.currency(12345.67, grouping=True, symbol=True))
'

export LC_ALL=pt_BR.utf8
nix run nixpkgs#python39 -- -c '
import locale
defaultlocale = locale.getdefaultlocale()
locale.setlocale(locale.LC_ALL, defaultlocale[0] + "." + defaultlocale[1])
print(locale.currency(12345.67, grouping=True, symbol=True))
'

Refs.:

• https://docs.python.org/3/library/locale.html#locale.getdefaultlocale

perl -MEncode=decode -E 'while(<>){ chomp; say length decode("UTF-8", $_) }' <<<'文字化け'

Refs.:

• https://stackoverflow.com/a/6192088

TODO:

• how is this locale is computed, system locale or internal to the Faker python library?
• How about the python PEP and packages tzdata and zoneinfo https://docs.python.org/3/library/zoneinfo.html https://pypi.org/project/tzdata/
• Live de Python #80 - Melhorando testes de unidade com Faker, Factory boy e Hypothesis, t=875s
• Java: https://stackoverflow.com/a/62186308
• https://bugs.python.org/issue19846
• https://bugs.python.org/issue28180

Faker("cellphone_number", locale="pt-BR")

TODO:

• https://github.com/systemd/systemd/blob/d9c6956ee4c10b76b4ed4ae32550e15a300172f3/mkosi.build#L27-L48 and systemd-escape -u 'Hall\xc3\xb6chen\x2c\x20Meister'
• https://stackoverflow.com/a/43989185
• https://pythonmana.com/2022/01/202201010619318735.html
• https://stackoverflow.com/questions/63019217/write-unicode-text-on-image-in-python-pillow
• https://stackoverflow.com/questions/40302497/erratic-localization-behavior-of-gnu-gettext-compared-to-strftime-or-printf
• https://stackoverflow.com/a/31970670
• https://stackoverflow.com/q/63019217
• https://stackoverflow.com/questions/64790054/how-to-specify-localized-forms-of-cjk-scripts-in-pythons-pil-imagefont
• https://unix.stackexchange.com/questions/101844/printing-utf-8-including-chinese-text
• https://unix.stackexchange.com/a/233158

[PedroRegisPOAR]

TODO:

At 31:50 you talk about environment variables. However there are some mistakes worth correcting for future viewers. First, although the environment variables are stored in the process' memory, it is stored as zero-terminated strings and not as one big string separated by new-line characters. It is also is not stored on the heap, nor is there a global variable in the data section pointing to it. The environment is actually stored entirely on the stack and is a part of the initial process stack that is set up before the program starts running. The first value on the stack is the argument count followed by an array of the addresses of the different arguments, then address 0 marking the end of the argument array. Right after that there is a second array of addresses which each point to a zero-terminated string which would be the environment variables, this array is also terminated by having address 0 at the end. There is actually a third array of auxiliary vectors but after that there is an unspecified amount of bytes before the information block starts. It's generally inside this block the command line arguments and environment variables are stored, as in the actual string values. You can confirm this by dumping the stack of pretty much any program and you typically find all the environment variables at the very end (highest memory address). If you are on Linux you can do this by first reading the '/proc//maps' file for any process, just replace with that process' PID. This file contains the ranges of memory mapped to the process and what they are mapped to. Near the bottom you'll see one line with the range mapped to [stack]. Take note of the start address and calculate how big it is in bytes. Then run 'sudo xxd -s -l /dev//mem', example 'sudo xxd -s 0x7fff182bd000 -l 0x22000 /dev/14950/mem'. And the environment variables should get printed out together with their hex values and address location.

To illustrate this further I've written a small c program that prints all the environment variables using the argv array pointer. As you can see the environment variable pointers are stored pretty much right after argv.

#include <stdio.h>
int main(int argc, char **argv)
{
 for (int i = argc + 2; argv[i] != NULL; i++)
 {
  printf("%s\n", argv[i]);
 }
 return 0;
}

You can of course make it less stupid by using the full version of main which includes a pointer to the first element in the environment pointer array.

#include <stdio.h>
int main(int argc, char **argv, char **envp)
{
 for (int i = 0; envp[i] != NULL; i++)
 {
  printf("%s\n", envp[i]);
 }
 return 0;
}

This is all defined as a part of the ABI (application binary interface) for both the x86 and x86_64 architecture, so 32 and 64 bit desktop computers.

tl;dr: The environment is not a single long string separated by new-line characters. The environment variables and the pointers to them are both stored on the stack or just before it.
https://www.youtube.com/watch?v=xHu7qI1gDPA&lc=UgwvbQ7HZFUEZ2EGQ7V4AaABAg

Maybe related: https://serverfault.com/a/792136

Related: Dangerous Code Hidden in Plain Sight for 12 years

[PedroRegisPOAR]

Fonts, yes they are related too

Yeah, here i am trying to summarize all this mess.

FC_LANG is used to specify the default language as the weak binding in the query. if this isn't set, the default language will be determined from current locale.
https://www.freedesktop.org/software/fontconfig/fontconfig-user.html

export FONTCONFIG_PATH=/etc/fonts

Refs.:

• https://askubuntu.com/a/708541

TODOs:

• https://stackoverflow.com/questions/39507534/statically-linking-fontconfig-disable-fonts-conf-file
• https://askubuntu.com/questions/202389/per-user-fonts-conf-file
• https://en.wikipedia.org/wiki/Fontconfig
• https://en.wikipedia.org/wiki/X_logical_font_description
• https://wiki.archlinux.org/title/XDG_Base_Directory
• How do I avoid mojibake in NixOS?

man fonts-conf

ls -al $(nix build --no-link --print-build-logs --print-out-paths github:NixOS/nixpkgs/0938d73bb143f4ae037143572f11f4338c7b2d1c#xorg.fontalias)/share/fonts/X11

Some really good videos

• Characters, Symbols and the Unicode Miracle - Computerphile
• Code Pages, Character Encoding, Unicode, UTF-8 and the BOM - Computer Stuff They Didn't Teach You #2
• What's a Carriage and Who's Feeding it Lines? CRLF - Computer Stuff They Didn't Teach You #1
• Internationalis(z)ing Code - Computerphile
• The Problem with Time & Timezones - Computerphile

Minimal working example (on my NixOS machine with zsh)

echo '\u2603'

LC_CTYPE=C echo '\u2603'

Refs.:

• Recent update, agnoster with powerline font, character not in range ohmyzsh/ohmyzsh#4065 (comment)

Errors out:

zsh: character not in range

Also, UTF-8 is not a valid POSIX locale. It may work on some systems, but Arch Linux might not like it. en_US.UTF-8 is valid. Try putting that at the beginning of the line, and using LC_ALL instead of LC_CTYPE.
ohmyzsh/ohmyzsh#4065 (comment)

We ended up just giving up on trying to fix broken locales, thanks for your contribution and your patience.
ohmyzsh/ohmyzsh#4696 (comment)

Must read

Main ones:

• https://medium.com/@wanxiao1994/some-trivial-knowledge-about-unicode-4f70750af0ba
• https://esham.io/2014/06/unicode-flags
• https://esham.io/2015/04/emoji-flags-redux
• https://superuser.com/a/1266865
• https://shkspr.mobi/blog/2019/06/quirks-and-limitations-of-emoji-flags/
• https://qz.com/2148267/the-reason-why-unicode-wont-add-new-flag-emoji
• https://superuser.com/questions/1676773/how-do-i-preview-a-string-containing-unsupported-unicode-characters/1676816#1676816
• https://unix.stackexchange.com/questions/535858/test-for-terminal-emoji-support#comment993467_535858
• Recent update, agnoster with powerline font, character not in range ohmyzsh/ohmyzsh#4065 (comment)
• Recent update, agnoster with powerline font, character not in range ohmyzsh/ohmyzsh#4065 (comment)
• Recent update, agnoster with powerline font, character not in range ohmyzsh/ohmyzsh#4065 (comment)
• Recent update, agnoster with powerline font, character not in range ohmyzsh/ohmyzsh#4065 (comment)
• https://unix.stackexchange.com/a/285002
• fonts.fontconfig.defaultFonts.emoji does not work for some fonts NixOS/nixpkgs#86713 (comment)
• fontconfig: Enable color emoji as a fallback NixOS/nixpkgs#86601 (comment)
• https://spaceship-prompt.sh/faq/
• https://superuser.com/questions/1545566/is-there-any-way-to-replace-segoe-ui-emoji-that-comes-with-windows-with-a-font-t

Tables:

• https://unicode.org/Public/emoji/
• https://github.com/posoo/emojify-zsh/blob/53e13ef234b713e9d4839c5b4e0bdb375fed6fe7/emojify#L28-L2793
• https://github.com/DiegoFleitas/DeviantBot/wiki/Emojis
• https://getemoji.com/
• https://apps.timwhitlock.info/emoji/tables/iso3166
• https://emojipedia.org/emoji-flag-sequence/
• https://en.wikipedia.org/wiki/Regional_indicator_symbol
• https://tug.ctan.org/info/symbols/comprehensive/symbols-a4.pdf

Fonts:

• https://stackoverflow.com/a/40896083
• https://unicode.org/resources/fonts.html
• https://blog.emojipedia.org/exploring-googles-new-black-and-blobby-emoji-font/
• https://fonts.google.com/noto/use#how-are-noto-fonts-organized
• https://www.babelstone.co.uk/Fonts/Flags.html
• https://www.fontspace.com/unicode/char/200C-zero-width-non-joiner
• https://github.com/adobe-fonts/emojione-color
• https://stackoverflow.com/a/72731942
• https://superuser.com/a/1266892
• https://nolanlawson.com/2022/04/08/the-struggle-of-using-native-emoji-on-the-web/
• https://superuser.com/a/1671164
• TODO: https://askubuntu.com/a/740649

More python focused:

• https://docs.python.org/3/library/unicodedata.html
• https://docs.python.org/3/howto/unicode.html
• https://www.geeksforgeeks.org/unicodedata-unicode-database-python/
• https://www.geeksforgeeks.org/unicode_literals-in-python/
• https://www.geeksforgeeks.org/python-convert-string-to-unicode-characters/
• https://stackoverflow.com/a/44457367
• https://stackoverflow.com/a/58200269
• https://github.com/cvzi/flag
• https://www.johndcook.com/blog/2022/10/02/flags-unicode/
• https://www.fluentpython.com/extra/multi-character-emojis/
• https://note.nkmk.me/en/python-chr-ord-unicode-code-point/
• https://davidamos.dev/why-cant-you-reverse-a-flag-emoji/
• https://gist.github.com/treyhunner/8261108b7d333132b544807ee3ffd55a

Even Julia:

• https://discourse.julialang.org/t/recommendation-for-a-font-with-good-unicode-support/39885

Of course LaTeX:

• https://tex.stackexchange.com/questions/352623/unicode-char-u200b
• https://pt.overleaf.com/learn/latex/Questions/Inserting_emojis_in_LaTeX_documents_on_Overleaf

Linux:

• https://forum.manjaro.org/t/howto-enable-emoji-fonts/36695/6
• https://chrpaul.de/2019/07/Enable-colour-emoji-support-on-Manjaro-Linux.html
• https://askubuntu.com/questions/1130880/color-emojis-working-partially-on-18-04
• Are there emoji missing? (Example: the English flag 🏴󠁧󠁢󠁥󠁮󠁧󠁿) maoschanz/emoji-selector-for-gnome#86
• https://pkgs.alpinelinux.org/package/edge/community/x86/font-noto-emoji
• https://briancaffey.github.io/2017/11/24/how-to-get-color-emoji-in-arch-linux.html/
• https://forum.manjaro.org/t/howto-enable-emoji-fonts/36695/4
• https://opensource.com/article/21/2/emoji-linux
• https://victor.kropp.name/blog/emoji-on-linux/
• https://mobile.twitter.com/XTaran/status/1536751836425756675

Troubleshooting

fc-cache -fv

echo "\ue0b0 \ue0a0 \u2b80 \u00b1 \u27a6 \u2718 \u26a1 \u2699"
echo ##1##
echo '\ue0b0 \ue0a0 \u2b80 \u00b1 \u27a6 \u2718 \u26a1 \u2699'
echo ##2##
echo -e '\ue0b0 \ue0a0 \u2b80 \u00b1 \u27a6 \u2718 \u26a1 \u2699'
echo ##3##
echo -e "\ue0b0 \ue0a0 \u2b80 \u00b1 \u27a6 \u2718 \u26a1 \u2699"

fc-list : family

fc-match -s emoji

localectl status

Outputs:

   System Locale: LANG=en_US.UTF-8
                  LC_MONETARY=pt_BR.UTF-8
       VC Keymap: us
      X11 Layout: br
       X11 Model: pc104
     X11 Variant: abnt2
     X11 Options: terminate:ctrl_alt_bksp

TODO:
https://ostechnix.com/install-nerd-fonts-to-add-glyphs-in-your-code-on-linux/
https://ostechnix.com/find-installed-fonts-commandline-linux/
ryanoasis/nerd-fonts#485 (comment)
ryanoasis/nerd-fonts#485 (comment)

pango-view

NixOS/nixpkgs#86601 (comment)

The echo/print stuff

echo -e "\U1f3f4\Ue0067\Ue0062\Ue0077\Ue006c\Ue0073\Ue007f"
echo #####
echo -e "\U1f9df\U200d\U2640\Ufe0f"

EMOJIS=(🥯  🦆 🦉 🥓 🦄 🦀 🖕 🍣 🍤 🍥 🍡 🥃 🥞 🤯 🤪 🤬 🤮 🤫 🤭 🧐 🐕 🦖 👾 🐉 🐓 🐋 🐌 🐢)
echo $EMOJIS

UNICORN='\U1F984'; THUMBS_UP='\U1F44D'; echo -e "Riding an ${UNICORN} (${THUMBS_UP})"

Refs.:

• TODO

It should output 🍁:

echo -e '\xF0\x9F\x8D\x81'

Refs.:

• https://unix.stackexchange.com/questions/284990/can-a-script-determine-which-characters-a-terminal-can-display

toon=$'\U1F479'
print -r ${(l:${(m)#toon}:: :)}$'XYZ\n'$toon' ^-- must point to Y'

Refs.:

• https://www.zsh.org/mla/users/2020/msg00271.html

echo "a\uf240 abc"

Refs.:

• Some symbol glyphs show up as clipped. ryanoasis/nerd-fonts#442 (comment)

text="Éé"; echo ${#text}

LC_CTYPE=C text="Éé"; echo ${#text}

Refs.:

• https://unix.stackexchange.com/questions/245013/get-the-display-width-of-a-string-of-characters/245043#comment1035649_245043
• https://unix.stackexchange.com/questions/245013/get-the-display-width-of-a-string-of-characters/245043#comment1035796_245043

echo \
'\U1F479' \
'\xF0\x9F\x8D\x81' \
'\U1f9df\U200d' \
'\U1F984' \
'\U1F44D' \
'\U1F9DA' \
'\U1F426' \
'\U1F99C' \
'\U1F996' \
'\U1F420' \
'\U1F41E' \
'\U1F340' \
'\U1F308' \
'\U1F965' \
'\U1F37F' \
'\U1F991' \
'\U1F37A' \
'\U1F692' \
'\U1F6F3' \
'\U26A1' \
'\U1F4A7' \
'\U1F537'

Outputs: 👹 🍁 🧟‍ 🦄 👍 🧚 🐦 🦜 🦖 🐠 🐞 🍀 🌈 🥥 🍿 🦑 🍺 🚒 🛳 ⚡ 💧 🔷

Some flags shows:

echo \
'\U1F3F4\UE0067\UE0062\UE0065\UE006E\UE0067\UE007F' \
'\U1F3F4\UE0067\UE0062\UE0073\UE0063\UE0074\UE007F' \
'\U1f3f4\Ue0067\Ue0062\Ue0077\Ue006c\Ue0073\Ue007f'

Outputs: 🏴󠁧󠁢󠁥󠁮󠁧󠁿 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🏴󠁧󠁢󠁷󠁬󠁳󠁿

Some flags are broken:

echo \
'\U1F3F3\UFE0F\U200D\U1F308' \
'\U1F1E7\U1F1F7'

Outputs:

But copying it directly from terminal to here in browser it renders correctly: 🏳️‍🌈 🇧🇷

The Japan flag, for example:

echo -e '\U1f1ef\U1f1f5' | hexdump -C

Refs.:

• TODO

TODO: test it

env \
FONTCONFIG_FILE=$PWD/etc-fonts/fonts.conf \
FC_DEBUG=1024 \
pango-view --text="Příliš 😂" --font='"Noto Color Emoji" 20'

Refs.:

• fontconfig: Enable color emoji as a fallback NixOS/nixpkgs#86601 (comment)

xterm -fa 'Dank Mono' -fs 11

Refs.:

• https://unix.stackexchange.com/a/609609

TODO: impressive awk-fu
https://unix.stackexchange.com/a/526681

TODO: it is python code: https://stackoverflow.com/a/37362046

TODO: curl and the '\U0001F514' https://stackoverflow.com/a/55863437

TODO: teste Fira Code + JetBrains Mono