Add colors-256 script

This commit is contained in:
ItsDrike 2024-06-21 15:31:29 +02:00
parent 486f7376b2
commit 58731c52fb
Signed by: ItsDrike
GPG key ID: FA2745890B7048C0
4 changed files with 112 additions and 0 deletions

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@ -8,5 +8,6 @@ in {
home.packages = with scriptPkgs; [ home.packages = with scriptPkgs; [
bitcoin bitcoin
cheatsh cheatsh
colors256
]; ];
} }

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@ -0,0 +1,101 @@
#!/usr/bin/env bash
# # Print out 256 colors, with each number printed in its corresponding colour
#
# This file is uploaded on <https://gist.githubusercontent.com/HaleTom/89ffe32783f89f403bba96bd7bcd1263/raw/>
# It was originally intended to be used as an alias that curled this URL and piped it into bash, however
# this is very unsafe as the owner can change the content of this gist at his convenience, meaning it was
# a potential security vulnerability. This is a script version of this alias to avoid this issue.
#
# The copyright for this file belongs to the original author: Tom Hale, 2016
# This file was released under MIT license
set -eu # Fail on errors or undeclared variables
printable_colours=256
# Return a colour that contrasts with the given colour
# Bash only does integer division, so keep it integral
function contrast_colour {
colour="$1"
if ((colour < 16)); then # Initial 16 ANSI colours
((colour == 0)) && printf "15" || printf "0"
return
fi
# Greyscale # rgb_R = rgb_G = rgb_B = (number - 232) * 10 + 8
if ((colour > 231)); then # Greyscale ramp
((colour < 244)) && printf "15" || printf "0"
return
fi
# All other colours:
# 6x6x6 colour cube = 16 + 36*R + 6*G + B # Where RGB are [0..5]
# See http://stackoverflow.com/a/27165165/5353461
# r=$(( (colour-16) / 36 ))
g=$((((colour - 16) % 36) / 6))
# b=$(( (colour-16) % 6 ))
# If luminance is bright, print number in black, white otherwise.
# Green contributes 587/1000 to human perceived luminance - ITU R-REC-BT.601
((g > 2)) && printf "0" || printf "15"
return
# Uncomment the below for more precise luminance calculations
# # Calculate percieved brightness
# # See https://www.w3.org/TR/AERT#color-contrast
# # and http://www.itu.int/rec/R-REC-BT.601
# # Luminance is in range 0..5000 as each value is 0..5
# luminance=$(( (r * 299) + (g * 587) + (b * 114) ))
# (( $luminance > 2500 )) && printf "0" || printf "15"
}
# Print a coloured block with the number of that colour
function print_colour {
local colour="$1" contrast
contrast=$(contrast_colour "$1")
printf "\e[48;5;%sm" "$colour" # Start block of colour
printf "\e[38;5;%sm%3d" "$contrast" "$colour" # In contrast, print number
printf "\e[0m " # Reset colour
}
# Starting at $1, print a run of $2 colours
function print_run {
local i
for ((i = "$1"; i < "$1" + "$2" && i < printable_colours; i++)); do
print_colour "$i"
done
printf " "
}
# Print blocks of colours
function print_blocks {
local start="$1" i
local end="$2" # inclusive
local block_cols="$3"
local block_rows="$4"
local blocks_per_line="$5"
local block_length=$((block_cols * block_rows))
# Print sets of blocks
for ((i = start; i <= end; i += (blocks_per_line - 1) * block_length)); do
printf "\n" # Space before each set of blocks
# For each block row
for ((row = 0; row < block_rows; row++)); do
# Print block columns for all blocks on the line
for ((block = 0; block < blocks_per_line; block++)); do
print_run $((i + (block * block_length))) "$block_cols"
done
((i += block_cols)) # Prepare to print the next row
printf "\n"
done
done
}
print_run 0 16 # The first 16 colours are spread over the whole spectrum
printf "\n"
print_blocks 16 231 6 6 3 # 6x6x6 colour cube between 16 and 231 inclusive
print_blocks 232 255 12 2 1 # Not 50, but 24 Shades of Grey

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@ -0,0 +1,9 @@
{pkgs, ...}:
(pkgs.writeShellApplication {
name = "colors-256";
runtimeInputs = with pkgs; [coreutils];
text = ''
${builtins.readFile ./colors-256.sh}
'';
})

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@ -5,6 +5,7 @@
packages = { packages = {
bitcoin = pkgs.callPackage ./bitcoin.nix {}; bitcoin = pkgs.callPackage ./bitcoin.nix {};
cheatsh = pkgs.callPackage ./cheatsh {}; cheatsh = pkgs.callPackage ./cheatsh {};
colors256 = pkgs.callPackage ./colors256 {};
}; };
in in
packages packages