ladybird/Userland/Utilities/gzip.cpp
Rummskartoffel ba0d46e31a gzip: Don't fail when trying to compress empty files
Given an empty file, gzip would try to create a zero-size memory mapping
of that file, which would fail with EINVAL.
2022-01-08 15:29:38 +01:00

86 lines
3.1 KiB
C++

/*
* Copyright (c) 2021, Idan Horowitz <idan.horowitz@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibCompress/Gzip.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/FileStream.h>
#include <LibCore/MappedFile.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <unistd.h>
ErrorOr<int> serenity_main(Main::Arguments arguments)
{
Vector<StringView> filenames;
bool keep_input_files { false };
bool write_to_stdout { false };
bool decompress { false };
Core::ArgsParser args_parser;
args_parser.add_option(keep_input_files, "Keep (don't delete) input files", "keep", 'k');
args_parser.add_option(write_to_stdout, "Write to stdout, keep original files unchanged", "stdout", 'c');
args_parser.add_option(decompress, "Decompress", "decompress", 'd');
args_parser.add_positional_argument(filenames, "Files", "FILES");
args_parser.parse(arguments);
if (write_to_stdout)
keep_input_files = true;
for (auto const& input_filename : filenames) {
String output_filename;
if (decompress) {
if (!input_filename.ends_with(".gz"sv)) {
warnln("unknown suffix for: {}, skipping", input_filename);
continue;
}
output_filename = input_filename.substring_view(0, input_filename.length() - ".gz"sv.length());
} else {
output_filename = String::formatted("{}.gz", input_filename);
}
// We map the whole file instead of streaming to reduce size overhead (gzip header) and increase the deflate block size (better compression)
// TODO: automatically fallback to buffered streaming for very large files
RefPtr<Core::MappedFile> file;
ReadonlyBytes input_bytes;
if (TRY(Core::System::stat(input_filename)).st_size > 0) {
file = TRY(Core::MappedFile::map(input_filename));
input_bytes = file->bytes();
}
AK::Optional<ByteBuffer> output_bytes;
if (decompress)
output_bytes = Compress::GzipDecompressor::decompress_all(input_bytes);
else
output_bytes = Compress::GzipCompressor::compress_all(input_bytes);
if (!output_bytes.has_value()) {
warnln("Failed gzip {} input file", decompress ? "decompressing"sv : "compressing"sv);
return 1;
}
auto success = false;
if (write_to_stdout) {
auto stdout = Core::OutputFileStream { Core::File::standard_output() };
success = stdout.write_or_error(output_bytes.value());
} else {
auto output_stream_result = Core::OutputFileStream::open(output_filename);
if (output_stream_result.is_error()) {
warnln("Failed opening output file for writing: {}", output_stream_result.error());
return 1;
}
success = output_stream_result.value().write_or_error(output_bytes.value());
}
if (!success) {
warnln("Failed writing to output");
return 1;
}
if (!keep_input_files) {
TRY(Core::System::unlink(input_filename));
}
}
return 0;
}