// // Copyright(c) 2015 Gabi Melman. // Distributed under the MIT License (http://opensource.org/licenses/MIT) // spdlog usage example #include "spdlog/spdlog.h" #include #include void stdout_logger_example(); void basic_example(); void rotating_example(); void daily_example(); void async_example(); void binary_example(); void trace_example(); void multi_sink_example(); void user_defined_example(); void err_handler_example(); void syslog_example(); constexpr int magic_2{2}; constexpr int magic_3{3}; constexpr int magic_10{10}; constexpr int magic_12{12}; constexpr int magic_14{14}; constexpr int magic_30{30}; constexpr int magic_42{42}; constexpr int magic_100{100}; constexpr int five_MB{5 * 1024 * 1024}; constexpr float magic_float{1.23456F}; constexpr long double pi{3.14159265358979323846264L}; // https://en.cppreference.com/w/cpp/language/user_literal // Note: use '-fext-numeric-literals' to enable more built-in suffixes // used as conversion #if 0 constexpr long double operator"" _deg(long double deg) { return deg * pi / 180; } constexpr size_t operator"" _MB(size_t n) { return n * 1024 * 1024; } #endif int main() { spdlog::info("Welcome to spdlog version {}.{}.{} !", SPDLOG_VER_MAJOR, SPDLOG_VER_MINOR, SPDLOG_VER_PATCH); spdlog::warn("Easy padding in numbers like {:08d}", magic_12); spdlog::critical("Support for int: {0:d}; hex: {0:x}; oct: {0:o}; bin: {0:b}", magic_42); spdlog::info("Support for floats {:03.2f}", magic_float); spdlog::info("Positional args are {1} {0}..", "too", "supported"); spdlog::info("{:>8} aligned, {:<8} aligned", "right", "left"); // Runtime log levels spdlog::set_level(spdlog::level::info); // Set global log level to info spdlog::debug("This message should not be displayed!"); spdlog::set_level(spdlog::level::trace); // Set specific logger's log level spdlog::debug("This message should be displayed.."); // Customize msg format for all loggers spdlog::set_pattern("[%H:%M:%S %z] [%^%L%$] [thread %t] %v"); spdlog::info("This an info message with custom format"); spdlog::set_pattern("%+"); // back to default format spdlog::set_level(spdlog::level::info); // Backtrace support // Loggers can store in a ring buffer all messages (including debug/trace) for later inspection. // When needed, call dump_backtrace() to see what happened: spdlog::enable_backtrace(magic_10); // create ring buffer with capacity of 10 messages for (int i = 0; i < magic_100; i++) { spdlog::debug("Backtrace message {}", i); // not logged.. } // e.g. if some error happened: spdlog::dump_backtrace(); // log them now! try { stdout_logger_example(); basic_example(); rotating_example(); daily_example(); async_example(); binary_example(); multi_sink_example(); user_defined_example(); err_handler_example(); trace_example(); using namespace std::chrono_literals; // C++14 // Flush all *registered* loggers using a worker thread every 3 seconds. // note: registered loggers *must* be thread safe for this to work correctly! spdlog::flush_every((3s)); // Apply some function on all registered loggers spdlog::apply_all([&](std::shared_ptr l) { l->info("End of example."); }); // Release all spdlog resources, and drop all loggers in the registry. // This is optional (only mandatory if using windows + async log). spdlog::shutdown(); } // Exceptions will only be thrown upon failed logger or sink construction (not during logging). catch (const spdlog::spdlog_ex &ex) { std::printf("Log initialization failed: %s\n", ex.what()); return 1; } } #include "spdlog/sinks/stdout_color_sinks.h" // or #include "spdlog/sinks/stdout_sinks.h" if no colors needed. void stdout_logger_example() { // Create color multi threaded logger. auto console = spdlog::stdout_color_mt("console"); // or for stderr: // auto console = spdlog::stderr_color_mt("error-logger"); } #include "spdlog/sinks/basic_file_sink.h" void basic_example() { // Create basic file logger (not rotated). auto my_logger = spdlog::basic_logger_mt("file_logger", "logs/basic-log.txt"); } #include "spdlog/sinks/rotating_file_sink.h" void rotating_example() { // Create a file rotating logger with 5mb size max and 3 rotated files. auto rotating_logger = spdlog::rotating_logger_mt("some_logger_name", "logs/rotating.txt", five_MB, magic_3); } #include "spdlog/sinks/daily_file_sink.h" void daily_example() { // Create a daily logger - a new file is created every day on 2:30am. auto daily_logger = spdlog::daily_logger_mt("daily_logger", "logs/daily.txt", magic_2, magic_30); } #include "spdlog/async.h" void async_example() { // Default thread pool settings can be modified *before* creating the async logger: // spdlog::init_thread_pool(32768, 1); // queue with max 32k items 1 backing thread. auto async_file = spdlog::basic_logger_mt("async_file_logger", "logs/async_log.txt"); // alternatively: // auto async_file = spdlog::create_async("async_file_logger", "logs/async_log.txt"); constexpr int loops{101}; for (int i = 1; i < loops; ++i) { async_file->info("Async message #{}", i); } } // Log binary data as hex. // Many types of std::container types can be used. // Iterator ranges are supported too. // Format flags: // {:X} - print in uppercase. // {:s} - don't separate each byte with space. // {:p} - don't print the position on each line start. // {:n} - don't split the output to lines. #include "spdlog/fmt/bin_to_hex.h" void binary_example() { constexpr int len{80}; std::vector buf(len); for (int i = 0; i < len; i++) { buf.push_back(static_cast(i & 0xff)); } spdlog::info("Binary example: {}", spdlog::to_hex(buf)); spdlog::info("Another binary example:{:n}", spdlog::to_hex(std::begin(buf), std::begin(buf) + magic_10)); // more examples: // logger->info("uppercase: {:X}", spdlog::to_hex(buf)); // logger->info("uppercase, no delimiters: {:Xs}", spdlog::to_hex(buf)); // logger->info("uppercase, no delimiters, no position info: {:Xsp}", spdlog::to_hex(buf)); } // Compile time log levels. // define SPDLOG_ACTIVE_LEVEL to required level (e.g. SPDLOG_LEVEL_TRACE) void trace_example() { // trace from default logger SPDLOG_TRACE("Some trace message.. {} ,{}", 1, pi); // debug from default logger SPDLOG_DEBUG("Some debug message.. {} ,{}", 1, pi); // trace from logger object auto logger = spdlog::get("file_logger"); SPDLOG_LOGGER_TRACE(logger, "another trace message"); } // A logger with multiple sinks (stdout and file) - each with a different format and log level. void multi_sink_example() { auto console_sink = std::make_shared(); console_sink->set_level(spdlog::level::warn); console_sink->set_pattern("[multi_sink_example] [%^%l%$] %v"); auto file_sink = std::make_shared("logs/multisink.txt", true); file_sink->set_level(spdlog::level::trace); spdlog::logger logger("multi_sink", {console_sink, file_sink}); logger.set_level(spdlog::level::debug); logger.warn("this should appear in both console and file"); logger.info("this message should not appear in the console, only in the file"); } // User defined types logging by implementing operator<< #include "spdlog/fmt/ostr.h" // must be included struct my_type { int i; template friend OStream &operator<<(OStream &os, const my_type &c) { return os << "[my_type i=" << c.i << "]"; } }; void user_defined_example() { spdlog::info("user defined type: {}", my_type{magic_14}); } // Custom error handler. Will be triggered on log failure. void err_handler_example() { // can be set globally or per logger(logger->set_error_handler(..)) spdlog::set_error_handler([](const std::string &msg) { printf("*** Custom log error handler: %s ***\n", msg.c_str()); }); } // syslog example (linux/osx/freebsd) #ifndef _WIN32 #include "spdlog/sinks/syslog_sink.h" void syslog_example() { std::string ident = "spdlog-example"; auto syslog_logger = spdlog::syslog_logger_mt("syslog", ident, LOG_PID); syslog_logger->warn("This is warning that will end up in syslog."); } #endif // Android example. #if defined(__ANDROID__) #include "spdlog/sinks/android_sink.h" void android_example() { std::string tag = "spdlog-android"; auto android_logger = spdlog::android_logger_mt("android", tag); android_logger->critical("Use \"adb shell logcat\" to view this message."); } #endif