Method initialize

userspace/programs/Shell/Builtin.cpp:13–272

#define ERROR_RETURN(__msg, __ret) do { perror(__msg); return __ret; } while (false)

void Builtin::initialize()
{
	MUST(m_builtin_commands.emplace("clear"_sv,
		[](Execute&, BAN::Span<const BAN::String>, FILE*, FILE* fout) -> int
		{
			fprintf(fout, "\e[H\e[3J\e[2J");
			fflush(fout);
			return 0;
		}, true
	));

	MUST(m_builtin_commands.emplace("exit"_sv,
		[](Execute&, BAN::Span<const BAN::String> arguments, FILE*, FILE*) -> int
		{
			int exit_code = 0;
			if (arguments.size() > 1)
			{
				auto exit_string = arguments[1].sv();
				for (size_t i = 0; i < exit_string.size() && isdigit(exit_string[i]); i++)
					exit_code = (exit_code * 10) + (exit_string[i] - '0');
			}
			exit(exit_code);
			ASSERT_NOT_REACHED();
		}, true
	));

	MUST(m_builtin_commands.emplace("exec"_sv,
		[](Execute&, BAN::Span<const BAN::String> arguments, FILE*, FILE*) -> int
		{
			if (arguments.size() <= 1)
				return 0;

			BAN::Vector<const char*> argv;
			for (size_t i = 1; i < arguments.size(); i++)
				MUST(argv.push_back(arguments[i].data()));
			MUST(argv.push_back(nullptr));

			execvp(argv[0], const_cast<char* const*>(argv.data()));
			exit(128 + errno);
			ASSERT_NOT_REACHED();
		}, true
	));

	MUST(m_builtin_commands.emplace("export"_sv,
		[](Execute&, BAN::Span<const BAN::String> arguments, FILE*, FILE*) -> int
		{
			for (size_t i = 1; i < arguments.size(); i++)
			{
				const auto argument = arguments[i].sv();

				const auto idx = argument.find('=');
				if (!idx.has_value())
					continue;

				auto name = BAN::String(argument.substring(0, idx.value()));
				const char* value = argument.data() + idx.value() + 1;
				if (setenv(name.data(), value, true) == -1)
					ERROR_RETURN("setenv", 1);