text: /*
   * Copyright (c) 2020, Sergey Bugaev <bugaevc@serenityos.org>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include <AK/StringView.h>
  #include <LibCore/CArgsParser.h>
  #include <stdio.h>
  #include <unistd.h>
  
  int main(int argc, char** argv)
  {
      const char* path = nullptr;
      const char* program = "/bin/Shell";
      int flags = -1;
  
      Core::ArgsParser args_parser;
      args_parser.add_positional_argument(path, "New root directory", "path");
      args_parser.add_positional_argument(program, "Program to run", "program", Core::ArgsParser::Required::No);
  
      Core::ArgsParser::Option option {
          true,
          "Mount options",
          "options",
          'o',
          "options",
          [&flags](const char* s) {
              flags = 0;
              Vector<StringView> parts = StringView(s).split_view(',');
              for (auto& part : parts) {
                  if (part == "defaults")
                      continue;
                  else if (part == "nodev")
                      flags |= MS_NODEV;
                  else if (part == "noexec")
                      flags |= MS_NOEXEC;
                  else if (part == "nosuid")
                      flags |= MS_NOSUID;
                  else if (part == "bind")
                      fprintf(stderr, "Ignoring -o bind, as it doesn't make sense for chroot\n");
                  else
                      return false;
              }
              return true;
          }
      };
      args_parser.add_option(move(option));
      args_parser.parse(argc, argv);
  
      if (chroot_with_mount_flags(path, flags) < 0) {
          perror("chroot");
          return 1;
      }
  
      if (chdir("/") < 0) {
          perror("chdir(/)");
          return 1;
      }
  
      execl(program, program, nullptr);
      perror("execl");
      return 1;
  }
  