@Override
  public GfshParseResult parse(String userInput) {
    String rawInput = convertToSimpleParserInput(userInput);
    // this tells the simpleParser not to interpret backslash as escaping character
    rawInput = rawInput.replace("\\", "\\\\");
    // User SimpleParser to parse the input
    ParseResult result = super.parse(rawInput);

    if (result == null) {
      // do a quick check for required arguments, since SimpleParser unhelpfully suggests everything
      String missingHelp = commandManager.getHelper().getMiniHelp(userInput);
      if (missingHelp != null) {
        System.out.println(missingHelp);
      }

      return null;
    }

    return new GfshParseResult(result.getMethod(), result.getInstance(), result.getArguments(),
        userInput);
  }
it's assumed that the quoted string should not have escaped quotes inside it.
geode-gfsh/src/main/java/org/apache/geode/management/internal/cli/GfshParser.java