C++日志库spdlog

# spdlog Very fast, header-only/compiled, C++ logging library. [](https://github.com/gabime/spdlog/actions/workflows/ci.yml)  [](https://ci.appveyor.com/project/gabime/spdlog) [](https://github.com/gabime/spdlog/releases/latest) ## Install #### Header-only version Copy the include [folder](https://github.com/gabime/spdlog/tree/v1.x/include/spdlog) to your build tree and use a C++11 compiler. #### Compiled version (recommended - much faster compile times) ```console $ git clone https://github.com/gabime/spdlog.git $ cd spdlog && mkdir build && cd build $ cmake .. && make -j ``` see example [CMakeLists.txt](https://github.com/gabime/spdlog/blob/v1.x/example/CMakeLists.txt) on how to use. ## Platforms * Linux, FreeBSD, OpenBSD, Solaris, AIX * Windows (msvc 2013+, cygwin) * macOS (clang 3.5+) * Android ## Package managers: * Debian: `sudo apt install libspdlog-dev` * Homebrew: `brew install spdlog` * MacPorts: `sudo port install spdlog` * FreeBSD: `pkg install spdlog` * Fedora: `dnf install spdlog` * Gentoo: `emerge dev-libs/spdlog` * Arch Linux: `pacman -S spdlog` * openSUSE: `sudo zypper in spdlog-devel` * vcpkg: `vcpkg install spdlog` * conan: `spdlog/[>=1.4.1]` * conda: `conda install -c conda-forge spdlog` * build2: ```depends: spdlog ^1.8.2``` ## Features * Very fast (see [benchmarks](#benchmarks) below). * Headers only or compiled * Feature-rich formatting, using the excellent [fmt](https://github.com/fmtlib/fmt) library. * Asynchronous mode (optional) * [Custom](https://github.com/gabime/spdlog/wiki/3.-Custom-formatting) formatting. * Multi/Single threaded loggers. * Various log targets: * Rotating log files. * Daily log files. * Console logging (colors supported). * syslog. * Windows event log. * Windows debugger (```OutputDebugString(..)```). * Log to Qt widgets ([example](#log-to-qt-with-nice-colors)). * Easily [extendable](https://github.com/gabime/spdlog/wiki/4.-Sinks#implementing-your-own-sink) with custom log targets. * Log filtering - log levels can be modified at runtime as well as compile time. * Support for loading log levels from argv or environment var. * [Backtrace](#backtrace-support) support - store debug messages in a ring buffer and display them later on demand. ## Usage samples #### Basic usage ```c++ #include "spdlog/spdlog.h" int main() { spdlog::info("Welcome to spdlog!"); spdlog::error("Some error message with arg: {}", 1); spdlog::warn("Easy padding in numbers like {:08d}", 12); spdlog::critical("Support for int: {0:d}; hex: {0:x}; oct: {0:o}; bin: {0:b}", 42); spdlog::info("Support for floats {:03.2f}", 1.23456); spdlog::info("Positional args are {1} {0}..", "too", "supported"); spdlog::info("{:<30}", "left aligned"); spdlog::set_level(spdlog::level::debug); // Set global log level to debug spdlog::debug("This message should be displayed.."); // change log pattern spdlog::set_pattern("[%H:%M:%S %z] [%n] [%^---%L---%$] [thread %t] %v"); // Compile time log levels // Note that this does not change the current log level, it will only // remove (depending on SPDLOG_ACTIVE_LEVEL) the call on the release code. SPDLOG_TRACE("Some trace message with param {}", 42); SPDLOG_DEBUG("Some debug message"); } ``` --- #### Create stdout/stderr logger object ```c++ #include "spdlog/spdlog.h" #include "spdlog/sinks/stdout_color_sinks.h" void stdout_example() { // create a color multi-threaded logger auto console = spdlog::stdout_color_mt("console"); auto err_logger = spdlog::stderr_color_mt("stderr"); spdlog::get("console")->info("loggers can be retrieved from a global registry using the spdlog::get(logger_name)"); } ``` --- #### Basic file logger ```c++ #include "spdlog/sinks/basic_file_sink.h" void basic_logfile_example() { try { auto logger = spdlog::basic_logger_mt("basic_logger", "logs/basic-log.txt"); } catch (const spdlog::spdlog_ex &ex) { std::cout << "Log init failed: " << ex.what() << std::endl; } } ``` --- #### Rotating files ```c++ #include "spdlog/sinks/rotating_file_sink.h" void rotating_example() { // Create a file rotating logger with 5 MB size max and 3 rotated files auto max_size = 1048576 * 5; auto max_files = 3; auto logger = spdlog::rotating_logger_mt("some_logger_name", "logs/rotating.txt", max_size, max_files); } ``` --- #### Daily files ```c++ #include "spdlog/sinks/daily_file_sink.h" void daily_example() { // Create a daily logger - a new file is created every day at 2:30 am auto logger = spdlog::daily_logger_mt("daily_logger", "logs/daily.txt", 2, 30); } ``` --- #### Backtrace support ```c++ // Debug messages can be stored in a ring buffer instead of being logged immediately. // This is useful to display debug logs only when needed (e.g. when an error happens). // When needed, call dump_backtrace() to dump them to your log. spdlog::enable_backtrace(32); // Store the latest 32 messages in a buffer. // or my_logger->enable_backtrace(32).. for(int i = 0; i < 100; i++) { spdlog::debug("Backtrace message {}", i); // not logged yet.. } // e.g. if some error happened: spdlog::dump_backtrace(); // log them now! show the last 32 messages // or my_logger->dump_backtrace(32).. ``` --- #### Periodic flush ```c++ // periodically flush all *registered* loggers every 3 seconds: // warning: only use if all your loggers are thread-safe ("_mt" loggers) spdlog::flush_every(std::chrono::seconds(3)); ``` --- #### Stopwatch ```c++ // Stopwatch support for spdlog #include "spdlog/stopwatch.h" void stopwatch_example() { spdlog::stopwatch sw; spdlog::debug("Elapsed {}", sw); spdlog::debug("Elapsed {:.3}", sw); } ``` --- #### Log binary data in hex ```c++ // many types of std::container types can be used. // 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 into lines. // {:a} - show ASCII if :n is not set. #include "spdlog/fmt/bin_to_hex.h" void binary_example() { auto console = spdlog::get("console"); std::array buf; console->info("Binary example: {}", spdlog::to_hex(buf)); console->info("Another binary example:{:n}", spdlog::to_hex(std::begin(buf), std::begin(buf) + 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)); } ``` --- #### Logger with multi sinks - each with a different format and log level ```c++ // create a logger with 2 targets, with different log levels and formats. // The console will show only warnings or errors, while the file will log all. 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 sho