clor

#!/usr/bin/env sh
#
# Add colors to strings.
# Usage:
#   tail -F /var/log/some.log | clor Some Text

ESC="$(printf '\033')"

show_help() {
  cat <<EOF
Usage:
  clor [opts] [texts ... ]
EOF
}

create_sedexp() {
  printf "%q" "s/($1)/${ESC}[1;3$2m\1${ESC}[0m/g"
}

main() {
  local params sed_cmd iter sed_exp
  params=()
  sed_cmd="sed"

  while (( "$#" )); do
    case "$1" in
      -h|--help)
        show_help
        exit 0
        ;;
      --)
        shift
        for param; do
          params+=("$param")
        done
        break
        ;;
      --*)
        echo "Error: Unsupported flag $1" >&2
        exit 1
        ;;
      *)
        params+=("$1")
        shift
        ;;
    esac
  done

  set -- "${params[@]}"

  iter=0
  for param; do
    sed_exp="$(create_sedexp "$param" "$(($iter%6+1))")"
    sed_cmd="${sed_cmd} -E -e ${sed_exp}"
    iter=$(($iter+1))
  done

  eval "$sed_cmd"
}

main "$@" || exit $?