ターミナルでの拡張色表示をプロンプトに生かす

# For setting color for my prompt.
# https://qiita.com/PruneMazui/items/8a023347772620025ad6
# https://gist.github.com/hyuki/3eef0b67e30f2839c1dd556e9f10c9c1
# https://snap.textfile.org/20190706230113/

PROMPT = %Q(export COLOR='%d';) + %q(PS1="[\[\e[38;5;${COLOR}m\]\u@HOSTNAME\[\e[0m\] \w] \\$ ")
256.times do |n|
  s = sprintf(PROMPT, n)
  printf("\e[38;5;%dm%s\e[m\n", n, s)
end