Utilities: Add an lzcat utility

Userland/Utilities/lzcat.cpp

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2023, Tim Schumacher <timschumi@gmx.de>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibCompress/Lzma.h>
+#include <LibCore/ArgsParser.h>
+#include <LibCore/File.h>
+#include <LibCore/System.h>
+#include <LibMain/Main.h>
+
+ErrorOr<int> serenity_main(Main::Arguments arguments)
+{
+    TRY(Core::System::pledge("rpath stdio"));
+
+    StringView filename;
+
+    Core::ArgsParser args_parser;
+    args_parser.set_general_help("Decompress and print an LZMA archive");
+    args_parser.add_positional_argument(filename, "File to decompress", "file");
+    args_parser.parse(arguments);
+
+    auto file = TRY(Core::File::open_file_or_standard_stream(filename, Core::File::OpenMode::Read));
+    auto stream = TRY(Compress::LzmaDecompressor::create_from_container(move(file)));
+
+    // Arbitrarily chosen buffer size.
+    Array<u8, 4096> buffer;
+    while (!stream->is_eof()) {
+        auto slice = TRY(stream->read_some(buffer));
+        out("{:s}", slice);
+    }
+
+    return 0;
+}