mpd/src/CommandLine.cxx

// SPDX-License-Identifier: GPL-2.0-or-later
// Copyright The Music Player Daemon Project

#include "config.h"
#include "CommandLine.hxx"
#include "GitVersion.hxx"
#include "ls.hxx"
#include "LogInit.hxx"
#include "Log.hxx"
#include "config/File.hxx"
#include "decoder/DecoderList.hxx"
#include "decoder/DecoderPlugin.hxx"
#include "output/Registry.hxx"
#include "output/OutputPlugin.hxx"
#include "input/Registry.hxx"
#include "input/InputPlugin.hxx"
#include "playlist/PlaylistRegistry.hxx"
#include "playlist/PlaylistPlugin.hxx"
#include "fs/AllocatedPath.hxx"
#include "fs/NarrowPath.hxx"
#include "fs/Traits.hxx"
#include "fs/FileSystem.hxx"
#include "fs/glue/StandardDirectory.hxx"
#include "event/Features.h"
#include "io/uring/Features.h"
#include "cmdline/OptionDef.hxx"
#include "cmdline/OptionParser.hxx"
#include "util/Domain.hxx"
#include "Version.h"

#ifdef _WIN32
#include "system/Error.hxx"
#endif

#ifdef ENABLE_DATABASE
#include "db/Registry.hxx"
#include "db/DatabasePlugin.hxx"
#include "storage/Registry.hxx"
#include "storage/StoragePlugin.hxx"
#endif

#ifdef ENABLE_NEIGHBOR_PLUGINS
#include "neighbor/Registry.hxx"
#include "neighbor/NeighborPlugin.hxx"
#endif

#include "encoder/Features.h"
#ifdef ENABLE_ENCODER
#include "encoder/EncoderList.hxx"
#include "encoder/EncoderPlugin.hxx"
#endif

#ifdef ENABLE_ARCHIVE
#include "archive/ArchiveList.hxx"
#include "archive/ArchivePlugin.hxx"
#endif

#include <fmt/core.h>

namespace {
#ifdef _WIN32
constexpr auto CONFIG_FILE_LOCATION = Path::FromFS(PATH_LITERAL("mpd\\mpd.conf"));
constexpr auto APP_CONFIG_FILE_LOCATION = Path::FromFS(PATH_LITERAL("conf\\mpd.conf"));
#else
constexpr auto USER_CONFIG_FILE_LOCATION1 = Path::FromFS(PATH_LITERAL(".mpdconf"));
constexpr auto USER_CONFIG_FILE_LOCATION2 = Path::FromFS(PATH_LITERAL(".mpd/mpd.conf"));
constexpr auto USER_CONFIG_FILE_LOCATION_XDG = Path::FromFS(PATH_LITERAL("mpd/mpd.conf"));
#endif
} // namespace

enum Option {
	OPTION_KILL,
	OPTION_NO_CONFIG,
	OPTION_NO_DAEMON,
#ifdef __linux__
	OPTION_SYSTEMD,
#endif
	OPTION_STDOUT,
	OPTION_STDERR,
	OPTION_VERBOSE,
	OPTION_VERSION,
	OPTION_HELP,
	OPTION_HELP2,
};

static constexpr OptionDef option_defs[] = {
	{"kill", "kill the currently running mpd session"},
	{"no-config", "don't read from config"},
	{"no-daemon", "don't detach from console"},
#ifdef __linux__
	{"systemd", "systemd service mode"},
#endif
	{"stdout", nullptr}, // hidden, compatibility with old versions
	{"stderr", "print messages to stderr"},
	{"verbose", 'v', "verbose logging"},
	{"version", 'V', "print version number"},
	{"help", 'h', "show help options"},
	{nullptr, '?', nullptr}, // hidden, standard alias for --help
};

static constexpr Domain cmdline_domain("cmdline");

[[noreturn]]
static void version()
{
	fmt::print("Music Player Daemon " VERSION " ({})"
		   "\n"
		   "Copyright 2003-2007 Warren Dukes <warren.dukes@gmail.com>\n"
		   "Copyright 2008-2021 Max Kellermann <max.kellermann@gmail.com>\n"
		   "This is free software; see the source for copying conditions.  There is NO\n"
		   "warranty; not even MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n",
		   GIT_VERSION);

#ifdef ENABLE_DATABASE
	fmt::print("\n"
		   "Database plugins:\n");

	for (auto i = database_plugins; *i != nullptr; ++i)
		fmt::print(" {}", (*i)->name);

	fmt::print("\n\n"
		   "Storage plugins:\n");

	for (auto i = storage_plugins; *i != nullptr; ++i)
		fmt::print(" {}", (*i)->name);

	fmt::print("\n");
#endif

#ifdef ENABLE_NEIGHBOR_PLUGINS
	fmt::print("\n"
		   "Neighbor plugins:\n");
	for (auto i = neighbor_plugins; *i != nullptr; ++i)
		fmt::print(" {}", (*i)->name);

#endif

	fmt::print("\n"
		   "\n"
		   "Decoder plugins:\n");

	for (const DecoderPlugin &plugin : GetAllDecoderPlugins()) {
		fmt::print(" [{}]", plugin.name);

		const char *const*suffixes = plugin.suffixes;
		if (suffixes != nullptr)
			for (; *suffixes != nullptr; ++suffixes)
				fmt::print(" {}", *suffixes);

		if (plugin.suffixes_function != nullptr)
			for (const auto &i : plugin.suffixes_function())
				printf(" %s", i.c_str());

		if (plugin.protocols != nullptr)
			for (const auto &i : plugin.protocols())
				fmt::print(" {}", i);

		fmt::print("\n");
	}

	fmt::print("\n"
		   "Filters:\n"
#ifdef ENABLE_LIBSAMPLERATE
		   " libsamplerate"
#endif
#ifdef ENABLE_SOXR
		   " soxr"
#endif
		   "\n\n"
		   "Tag plugins:\n"
#ifdef ENABLE_ID3TAG
		   " id3tag"
#endif
		   "\n\n"
		   "Output plugins:\n");
	for (const auto &plugin : GetAllAudioOutputPlugins()) {
		fmt::print(" {}", plugin.name);
	}
	fmt::print("\n"

#ifdef ENABLE_ENCODER
		   "\n"
		   "Encoder plugins:\n");
	for (const auto &plugin : GetAllEncoderPlugins()) {
		fmt::print(" {}", plugin.name);
	}
	fmt::print("\n"
#endif

#ifdef ENABLE_ARCHIVE
		   "\n"
		   "Archive plugins:\n");
	for (const auto &plugin : GetAllArchivePlugins()) {
		fmt::print(" [{}]", plugin.name);

		const char *const*suffixes = plugin.suffixes;
		if (suffixes != nullptr)
			for (; *suffixes != nullptr; ++suffixes)
				fmt::print(" {}", *suffixes);

		fmt::print("\n");
	}

	fmt::print(""
#endif

		   "\n"
		   "Input plugins:\n"
		   " file"
#ifdef HAVE_URING
		   " io_uring"
#endif
#ifdef ENABLE_ARCHIVE
		   " archive"
#endif
		);
	for (const InputPlugin &plugin : GetAllInputPlugins())
		fmt::print(" {}", plugin.name);

	fmt::print("\n\n"
		   "Playlist plugins:\n");
	for (const auto &plugin : GetAllPlaylistPlugins()) {
		fmt::print(" {}", plugin.name);
	}

	fmt::print("\n\n"
		   "Protocols:\n");
	print_supported_uri_schemes_to_fp(stdout);

	fmt::print("\n"
		   "Other features:\n"
#ifdef HAVE_AVAHI
		   " avahi"
#endif
#ifdef ENABLE_DBUS
		   " dbus"
#endif
#ifdef ENABLE_UDISKS
		   " udisks"
#endif
#ifdef USE_EPOLL
		   " epoll"
#endif
#ifdef HAVE_ICONV
		   " iconv"
#endif
#ifdef HAVE_ICU
		   " icu"
#endif
#ifdef ENABLE_INOTIFY
		   " inotify"
#endif
#ifdef HAVE_IPV6
		   " ipv6"
#endif
#ifdef ENABLE_SYSTEMD_DAEMON
		   " systemd"
#endif
#ifdef HAVE_TCP
		   " tcp"
#endif
#ifdef HAVE_UN
		   " un"
#endif
		   "\n");

	std::exit(EXIT_SUCCESS);
}

static void PrintOption(const OptionDef &opt)
{
	if (opt.HasShortOption())
		printf("  -%c, --%-12s%s\n",
		       opt.GetShortOption(),
		       opt.GetLongOption(),
		       opt.GetDescription());
	else
		printf("  --%-16s%s\n",
		       opt.GetLongOption(),
		       opt.GetDescription());
}

[[noreturn]]
static void help()
{
	fmt::print("Usage:\n"
		   "  mpd [OPTION...] [path/to/mpd.conf]\n"
		   "\n"
		   "Music Player Daemon - a daemon for playing music.\n"
		   "\n"
		   "Options:\n");

	for (const auto &i : option_defs)
		if(i.HasDescription()) // hide hidden options from help print
			PrintOption(i);

	std::exit(EXIT_SUCCESS);
}

class ConfigLoader
{
	ConfigData &config;

public:
	explicit ConfigLoader(ConfigData &_config) noexcept
		:config(_config) {}

	bool TryFile(Path path);
	bool TryFile(const AllocatedPath &base_path, Path path);
};

bool ConfigLoader::TryFile(Path path)
{
	if (FileExists(path)) {
		ReadConfigFile(config, path);
		return true;
	}
	return false;
}

bool ConfigLoader::TryFile(const AllocatedPath &base_path, Path path)
{
	if (base_path.IsNull())
		return false;
	auto full_path = base_path / path;
	return TryFile(full_path);
}

void
ParseCommandLine(int argc, char **argv, CommandLineOptions &options,
		 ConfigData &config)
{
	bool use_config_file = true;

	// First pass: handle command line options
	OptionParser parser(option_defs, argc, argv);
	while (auto o = parser.Next()) {
		switch (Option(o.index)) {
		case OPTION_KILL:
			options.kill = true;
			break;

		case OPTION_NO_CONFIG:
			use_config_file = false;
			break;

		case OPTION_NO_DAEMON:
#ifdef ENABLE_DAEMON
			options.daemon = false;
#endif
			break;

#ifdef __linux__
		case OPTION_SYSTEMD:
#ifdef ENABLE_DAEMON
			options.daemon = false;
#endif
			options.systemd = true;
			break;
#endif

		case OPTION_STDOUT:
		case OPTION_STDERR:
			options.log_stderr = true;
			break;

		case OPTION_VERBOSE:
			options.verbose = true;
			break;

		case OPTION_VERSION:
			version();

		case OPTION_HELP:
		case OPTION_HELP2:
			help();
		}
	}

	/* initialize the logging library, so the configuration file
	   parser can use it already */
	log_early_init(options.verbose);

	if (!use_config_file) {
		LogDebug(cmdline_domain,
			 "Ignoring config, using daemon defaults");
		return;
	}

	// Second pass: find non-option parameters (i.e. config file)
	const char *config_file = nullptr;
	for (const char *i : parser.GetRemaining()) {
		if (config_file == nullptr) {
			config_file = i;
			continue;
		}

		throw std::runtime_error("too many arguments");
	}

	if (config_file != nullptr) {
		/* use specified configuration file */
		ReadConfigFile(config, FromNarrowPath(config_file));
		return;
	}

	/* use default configuration file path */

	ConfigLoader loader(config);

	bool found =
#ifdef _WIN32
		loader.TryFile(GetUserConfigDir(), CONFIG_FILE_LOCATION) ||
		loader.TryFile(GetSystemConfigDir(), CONFIG_FILE_LOCATION) ||
		loader.TryFile(GetAppBaseDir(), APP_CONFIG_FILE_LOCATION);
#else
		loader.TryFile(GetUserConfigDir(),
			       USER_CONFIG_FILE_LOCATION_XDG) ||
		loader.TryFile(GetHomeDir(), USER_CONFIG_FILE_LOCATION1) ||
		loader.TryFile(GetHomeDir(), USER_CONFIG_FILE_LOCATION2) ||
		loader.TryFile(Path::FromFS(SYSTEM_CONFIG_FILE_LOCATION));
#endif
	if (!found)
		throw std::runtime_error("No configuration file found");
}