ladybird/Userland/df.cpp
Lenny Maiorani 765936ebae
Everywhere: Switch from (void) to [[maybe_unused]] (#4473)
Problem:
- `(void)` simply casts the expression to void. This is understood to
  indicate that it is ignored, but this is really a compiler trick to
  get the compiler to not generate a warning.

Solution:
- Use the `[[maybe_unused]]` attribute to indicate the value is unused.

Note:
- Functions taking a `(void)` argument list have also been changed to
  `()` because this is not needed and shows up in the same grep
  command.
2020-12-21 00:09:48 +01:00

103 lines
4.1 KiB
C++

/*
* 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();
[[maybe_unused]] auto total_inode_count = fs_object.get("total_inode_count").to_u32();
[[maybe_unused]] 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();
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;
}