text: /*
   * Copyright (c) 2018-2020, Andreas Kling <kling@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/ByteBuffer.h>
  #include <AK/JsonArray.h>
  #include <AK/JsonObject.h>
  #include <AK/NumberFormat.h>
  #include <AK/String.h>
  #include <AK/Vector.h>
  #include <LibCore/ArgsParser.h>
  #include <LibCore/File.h>
  #include <fcntl.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  static bool flag_human_readable = false;
  
  struct FileSystem {
      String fs;
      size_t total_block_count { 0 };
      size_t free_block_count { 0 };
      size_t total_inode_count { 0 };
      size_t free_inode_count { 0 };
      size_t block_size { 0 };
      String mount_point;
  };
  
  int main(int argc, char** argv)
  {
      Core::ArgsParser args_parser;
      args_parser.set_general_help("Display free disk space of each partition.");
      args_parser.add_option(flag_human_readable, "Print human-readable sizes", "human-readable", 'h');
      args_parser.parse(argc, argv);
  
      auto file = Core::File::construct("/proc/df");
      if (!file->open(Core::IODevice::ReadOnly)) {
          fprintf(stderr, "Failed to open /proc/df: %s\n", file->error_string());
          return 1;
      }
  
      if (flag_human_readable) {
          printf("Filesystem      Size        Used    Available   Mount point\n");
      } else {
          printf("Filesystem    Blocks        Used    Available   Mount point\n");
      }
  
      auto file_contents = file->read_all();
      auto json_result = JsonValue::from_string(file_contents);
      ASSERT(json_result.has_value());
      auto json = json_result.value().as_array();
      json.for_each([](auto& value) {
          auto fs_object = value.as_object();
          auto fs = fs_object.get("class_name").to_string();
          auto total_block_count = fs_object.get("total_block_count").to_u32();
          auto free_block_count = fs_object.get("free_block_count").to_u32();
          auto total_inode_count = fs_object.get("total_inode_count").to_u32();
          auto free_inode_count = fs_object.get("free_inode_count").to_u32();
          auto block_size = fs_object.get("block_size").to_u32();
          auto mount_point = fs_object.get("mount_point").to_string();
  
          (void)total_inode_count;
          (void)free_inode_count;
  
          printf("%-10s", fs.characters());
  
          if (flag_human_readable) {
              printf("%10s  ", human_readable_size(total_block_count * block_size).characters());
              printf("%10s   ", human_readable_size((total_block_count - free_block_count) * block_size).characters());
              printf("%10s   ", human_readable_size(free_block_count * block_size).characters());
          } else {
              printf("%10u  ", total_block_count);
              printf("%10u   ", total_block_count - free_block_count);
              printf("%10u   ", free_block_count);
          }
  
          printf("%s", mount_point.characters());
          printf("\n");
      });
  
      return 0;
  }
  