rgba2hex

#!/usr/bin/env bash

H_flag=false

usage() {
  echo "
  Usage: rgba2hex [OPTIONS] [RGBA CODE]

  OPTIONS:
  -H      remove hashtag from output

  RGBA CODE example:
  rgb(255, 12, 0)
  rgba(219, 200, 15, 0.2)"
}

while getopts "Hh" opt; do
  case "${opt}" in
    H) H_flag=true ;;
    h)
      usage
      exit 0
      ;;
    \?)
      usage
      exit 1
      ;;
  esac
done
shift $((OPTIND -1))

round() {
  echo $(printf %.$2f $(echo "scale=$2;(((10^$2)*$1)+0.5)/(10^$2)" | bc))
}

if [ -z "$1" ]; then
  echo "Please provide rgba code"
  exit 1
fi

rgbacheck=${1:0:4}
has_alpha=false

if [ $rgbacheck = "rgba" ]; then
  has_alpha=true
elif [ $rgbacheck = "rgb(" ]; then
  has_alpha=false
else
  echo "  Input is probably not an rgba code.
  It should either be of the format rgba(rrr, ggg, bbb, a.aa) or rgb(rrr, ggg, bbb).
  Terminating..."
  exit 1
fi

rawcode=$(echo $1 | cut -d '(' -f2- | tr -d ')')
rawred=$(echo $rawcode | cut -d ',' -f1)
rawgreen=$(echo $rawcode | cut -d ',' -f2)
rawblue=$(echo $rawcode | cut -d ',' -f3)
if [ ${#rawred} == 1 ]; then
  red=$(printf '0%x' $rawred)
else
  red=$(printf '%x' $rawred)
fi
if [ ${#rawgreen} == 1 ]; then
  green=$(printf '0%x' $rawgreen)
else
  green=$(printf '%x' $rawgreen)
fi
if [ ${#rawblue} == 1 ]; then
  blue=$(printf '0%x' $rawblue)
else
  blue=$(printf '%x' $rawblue)
fi

if [ $has_alpha = true ]; then
  rawalpha=$(echo $rawcode | cut -d ',' -f4)
  rawalpha=$(round $(echo "$rawalpha * 255" | bc) 0)
  if [ ${#rawalpha} == 1 ]; then
    alpha=$(printf '0%x' $rawalpha)
  else
    alpha=$(printf '%x' $rawalpha)
  fi

  if ($H_flag); then
    echo -n "$red$green$blue$alpha"
  else
    echo -n "#$red$green$blue$alpha"
  fi
else
  if ($H_flag); then
    echo -n "$red$green$blue"
  else
    echo -n "#$red$green$blue"
  fi
fi