Function getenv

sources/instance/type_ext.cpp:2158–2164

		}

		string getenv(const string &name)
		{
			const char *str = std::getenv(name.c_str());
			if (str == nullptr)
				throw lang_error("Environment variable \"" + name + "\" is not exist.");
			return str;
		}

		void exit(const numeric &exit_code)
		{