#!/bin/sh
##? ~/bin/hex2rgb - convert color hex to rgb
# '#C0FFEE' => 192 255 238
# 'DEADBEEF' => 222 173 190 239
# 'fab' => 255 170 187
# Shamelessly stolen from https://stackoverflow.com/questions/7253235/convert-hexadecimal-color-to-decimal-rgb-values-in-unix-shell-script/75643474#75643474


__hex2rgb() {
  # reset $1 to scrubbed hex: '#01efa9' becomes '01EFA9'
  set -- "$(echo "$1" | tr -d '#' | tr '[:lower:]' '[:upper:]')"
  START=0
  STR=
  while (( START < ${#1} )); do
    # double each char under len 6 : FAB => FFAABB
    if (( ${#1} < 6 )); then
      STR="$(printf "${1:${START}:1}%.0s" 1 2)"
      (( START += 1 ))
    else
      STR="${1:${START}:2}"
      (( START += 2 ))
    fi
    echo "ibase=16; ${STR}" | bc
  done
  unset START STR
}
__hex2rgb "$@"