Someone

for kind, key, val in getopt():
  case kind
    of cmdArgument:
      filename = key
    of cmdShortOption, cmdLongOption:
      case key:
        of "decode", "d": decodeflag = true
        of "ignore-garbage", "i": ignoregarbage = true
        of "wrap", "w":
          try:
            wrap = parseInt(val)
          except:
            echo "Could not parse Integer"
            quit(QuitFailure)
        of "help", "h": echo "base64 [-di] [-w N] [file]"
        else: discard
    of cmdEnd: discard
    else: discard