spdlog/1.8.2+2

[brief]

Fast C++ logging library.

Very fast, header-only/compiled, C++ logging library. Build Status  Build status Release

Install

Header only version

Copy the source folder to your build tree and use a C++11 compiler.

Static lib version (recommended - much faster compile times)

$ git clone https://github.com/gabime/spdlog.git
$ cd spdlog && mkdir build && cd build
$ cmake .. && make -j

see example CMakeLists.txt on how to use.

Platforms

Package managers:

Features

Usage samples

Basic usage

#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
    // define SPDLOG_ACTIVE_LEVEL to desired level
    SPDLOG_TRACE("Some trace message with param {}", 42);
    SPDLOG_DEBUG("Some debug message");
}


Create stdout/stderr logger object

#include "spdlog/spdlog.h"
#include "spdlog/sinks/stdout_color_sinks.h"
void stdout_example()
{
    // create 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

#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

#include "spdlog/sinks/rotating_file_sink.h"
void rotating_example()
{
    // Create a file rotating logger with 5mb 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


#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 logger = spdlog::daily_logger_mt("daily_logger", "logs/daily.txt", 2, 30);
}


Backtrace support

// Loggers can store in a ring buffer all messages (including debug/trace) and display later on demand.
// When needed, call dump_backtrace() to see them

spdlog::enable_backtrace(32); // Store the latest 32 messages in a buffer. Older messages will be dropped.
// 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

// 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

// 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

// many types of std::container<char> 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 to 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<char, 80> 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 different format and log level


// create 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<spdlog::sinks::stdout_color_sink_mt>();
    console_sink->set_level(spdlog::level::warn);
    console_sink->set_pattern("[multi_sink_example] [%^%l%$] %v");

    auto file_sink = std::make_shared<spdlog::sinks::basic_file_sink_mt>("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");
}

Asynchronous logging

#include "spdlog/async.h"
#include "spdlog/sinks/basic_file_sink.h"
void async_example()
{
    // default thread pool settings can be modified *before* creating the async logger:
    // spdlog::init_thread_pool(8192, 1); // queue with 8k items and 1 backing thread.
    auto async_file = spdlog::basic_logger_mt<spdlog::async_factory>("async_file_logger", "logs/async_log.txt");
    // alternatively:
    // auto async_file = spdlog::create_async<spdlog::sinks::basic_file_sink_mt>("async_file_logger", "logs/async_log.txt");   
}


Asynchronous logger with multi sinks

#include "spdlog/sinks/stdout_color_sinks.h"
#include "spdlog/sinks/rotating_file_sink.h"

void multi_sink_example2()
{
    spdlog::init_thread_pool(8192, 1);
    auto stdout_sink = std::make_shared<spdlog::sinks::stdout_color_sink_mt >();
    auto rotating_sink = std::make_shared<spdlog::sinks::rotating_file_sink_mt>("mylog.txt", 1024*1024*10, 3);
    std::vector<spdlog::sink_ptr> sinks {stdout_sink, rotating_sink};
    auto logger = std::make_shared<spdlog::async_logger>("loggername", sinks.begin(), sinks.end(), spdlog::thread_pool(), spdlog::async_overflow_policy::block);
    spdlog::register_logger(logger);
}

User defined types

// user defined types logging by implementing operator<<
#include "spdlog/fmt/ostr.h" // must be included
struct my_type
{
    int i;
    template<typename OStream>
    friend OStream &operator<<(OStream &os, const my_type &c)
    {
        return os << "[my_type i=" << c.i << "]";
    }
};

void user_defined_example()
{
    spdlog::get("console")->info("user defined type: {}", my_type{14});
}


User defined flags in the log pattern

// Log patterns can contain custom flags.
// the following example will add new flag '%*' - which will be bound to a <my_formatter_flag> instance.
#include "spdlog/pattern_formatter.h"
class my_formatter_flag : public spdlog::custom_flag_formatter
{
public:
    void format(const spdlog::details::log_msg &, const std::tm &, spdlog::memory_buf_t &dest) override
    {
        std::string some_txt = "custom-flag";
        dest.append(some_txt.data(), some_txt.data() + some_txt.size());
    }

    std::unique_ptr<custom_flag_formatter> clone() const override
    {
        return spdlog::details::make_unique<my_formatter_flag>();
    }
};

void custom_flags_example()
{    
    auto formatter = std::make_unique<spdlog::pattern_formatter>();
    formatter->add_flag<my_formatter_flag>('*').set_pattern("[%n] [%*] [%^%l%$] %v");
    spdlog::set_formatter(std::move(formatter));
}


Custom error handler

void err_handler_example()
{
    // can be set globally or per logger(logger->set_error_handler(..))
    spdlog::set_error_handler([](const std::string &msg) { spdlog::get("console")->error("*** LOGGER ERROR ***: {}", msg); });
    spdlog::get("console")->info("some invalid message to trigger an error {}{}{}{}", 3);
}


syslog

#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.");
}

Android example

#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.");
}

Load log levels from env variable or from argv

#include "spdlog/cfg/env.h"
int main (int argc, char *argv[])
{
    spdlog::cfg::load_env_levels();
    // or from command line:
    // ./example SPDLOG_LEVEL=info,mylogger=trace
    // #include "spdlog/cfg/argv.h" // for loading levels from argv
    // spdlog::cfg::load_argv_levels(argc, argv);
}

So then you can:

$ export SPDLOG_LEVEL=info,mylogger=trace
$ ./example

Benchmarks

Below are some benchmarks done in Ubuntu 64 bit, Intel i7-4770 CPU @ 3.40GHz

Synchronous mode

[info] **************************************************************
[info] Single thread, 1,000,000 iterations
[info] **************************************************************
[info] basic_st         Elapsed: 0.17 secs        5,777,626/sec
[info] rotating_st      Elapsed: 0.18 secs        5,475,894/sec
[info] daily_st         Elapsed: 0.20 secs        5,062,659/sec
[info] empty_logger     Elapsed: 0.07 secs       14,127,300/sec
[info] **************************************************************
[info] C-string (400 bytes). Single thread, 1,000,000 iterations
[info] **************************************************************
[info] basic_st         Elapsed: 0.41 secs        2,412,483/sec
[info] rotating_st      Elapsed: 0.72 secs        1,389,196/sec
[info] daily_st         Elapsed: 0.42 secs        2,393,298/sec
[info] null_st          Elapsed: 0.04 secs       27,446,957/sec
[info] **************************************************************
[info] 10 threads, competing over the same logger object, 1,000,000 iterations
[info] **************************************************************
[info] basic_mt         Elapsed: 0.60 secs        1,659,613/sec
[info] rotating_mt      Elapsed: 0.62 secs        1,612,493/sec
[info] daily_mt         Elapsed: 0.61 secs        1,638,305/sec
[info] null_mt          Elapsed: 0.16 secs        6,272,758/sec

Asynchronous mode

[info] -------------------------------------------------
[info] Messages     : 1,000,000
[info] Threads      : 10
[info] Queue        : 8,192 slots
[info] Queue memory : 8,192 x 272 = 2,176 KB 
[info] -------------------------------------------------
[info] 
[info] *********************************
[info] Queue Overflow Policy: block
[info] *********************************
[info] Elapsed: 1.70784 secs     585,535/sec
[info] Elapsed: 1.69805 secs     588,910/sec
[info] Elapsed: 1.7026 secs      587,337/sec
[info] 
[info] *********************************
[info] Queue Overflow Policy: overrun
[info] *********************************
[info] Elapsed: 0.372816 secs    2,682,285/sec
[info] Elapsed: 0.379758 secs    2,633,255/sec
[info] Elapsed: 0.373532 secs    2,677,147/sec

Documentation

Documentation can be found in the wiki pages.


Thanks to JetBrains for donating product licenses to help develop spdlog

version 1.8.2+2
license MITMIT License
repository https://pkg.cppget.org/1/stable
download spdlog-1.8.2+2.tar.gz
sha256 036b41612b777b6e4df90b58a5ebd7e33f29014ea85bb71d696fa1c25311ea23
project spdlog
doc-url github.com/gabime/spdlog/wiki
src-url github.com/gabime/spdlog
package-url github.com/build2-packaging/spdlog
package-email wmbat@protonmail.com
topics loggingC++

Depends (1)

fmt ^7.1.3

Requires (1)

c++ >= 11

Builds

toolchain public-0.16.0
target x86_64-apple-darwin22.5.0
tgt config macos_13-gcc_13_homebrew-static_O3
timestamp 2024-03-28 18:18:43 UTC (01:07:10 hours ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-apple-darwin22.5.0
tgt config macos_13-gcc_13_homebrew
timestamp 2024-03-28 18:16:54 UTC (01:08:59 hours ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-clang_15.0_libc++
timestamp 2024-03-28 10:26:26 UTC (08:59:27 hours ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-clang_15.0
timestamp 2024-03-28 10:25:26 UTC (09:00:26 hours ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-microsoft-win32-msvc14.3
tgt config windows_10-clang_16.0_llvm_msvc_17.6-static_O2
timestamp 2024-03-28 02:18:49 UTC (17:07:03 hours ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-microsoft-win32-msvc14.3
tgt config windows_10-msvc_17.6-static_O2
timestamp 2024-03-28 02:17:48 UTC (17:08:04 hours ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-microsoft-win32-msvc14.3
tgt config windows_10-clang_16.0_llvm_msvc_17.6-O2
timestamp 2024-03-28 02:14:21 UTC (17:11:31 hours ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-microsoft-win32-msvc14.3
tgt config windows_10-clang_16.0_llvm_msvc_17.6
timestamp 2024-03-28 02:10:41 UTC (17:15:11 hours ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-microsoft-win32-msvc14.3
tgt config windows_10-clang_15.0_msvc_msvc_17.6
timestamp 2024-03-28 02:09:56 UTC (17:15:57 hours ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-freebsd13.2
tgt config freebsd_13-clang_14.0-static_O3
timestamp 2024-03-28 02:05:56 UTC (17:19:57 hours ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-freebsd13.2
tgt config freebsd_13-clang_14.0-O3
timestamp 2024-03-28 02:03:26 UTC (17:22:27 hours ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-freebsd13.2
tgt config freebsd_13-clang_14.0
timestamp 2024-03-28 01:59:17 UTC (17:26:36 hours ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-freebsd12.4
tgt config freebsd_12-clang_13.0
timestamp 2024-03-28 01:58:58 UTC (17:26:55 hours ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-apple-darwin22.5.0
tgt config macos_13-clang_14.0-static_O3
timestamp 2024-03-27 16:09:30 UTC (01 03:16:23 days ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-apple-darwin22.5.0
tgt config macos_13-clang_14.0-O3
timestamp 2024-03-27 16:08:32 UTC (01 03:17:20 days ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-apple-darwin22.5.0
tgt config macos_13-clang_14.0
timestamp 2024-03-27 16:07:55 UTC (01 03:17:58 days ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_11-gcc_12.1
timestamp 2024-03-27 14:06:30 UTC (01 05:19:23 days ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-microsoft-win32-msvc14.3
tgt config windows_10-msvc_17.6-O2
timestamp 2024-03-27 12:18:40 UTC (01 07:07:13 days ago)
result warning (update) | log | rebuild
toolchain public-0.16.0
target x86_64-apple-darwin22.5.0
tgt config macos_13-gcc_13_homebrew-O3
timestamp 2024-03-27 12:10:19 UTC (01 07:15:33 days ago)
result error (test) | log | rebuild
toolchain public-0.16.0
target x86_64-microsoft-win32-msvc14.3
tgt config windows_10-msvc_17.6
timestamp 2024-03-27 12:09:41 UTC (01 07:16:12 days ago)
result warning (update) | log | rebuild
toolchain public-0.16.0
target x86_64-microsoft-win32-msvc14.3
tgt config windows_10-msvc_17.5
timestamp 2024-03-27 11:34:00 UTC (01 07:51:52 days ago)
result warning (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-clang_16.0_libc++-O3
timestamp 2024-03-27 11:08:04 UTC (01 08:17:48 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-clang_16.0_libc++-static_O3
timestamp 2024-03-27 11:07:13 UTC (01 08:18:39 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-clang_16.0-static_O3
timestamp 2024-03-27 11:06:53 UTC (01 08:19:00 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-clang_16.0_libc++
timestamp 2024-03-27 11:06:14 UTC (01 08:19:39 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-clang_16.0
timestamp 2024-03-27 11:05:29 UTC (01 08:20:23 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-clang_16.0-O3
timestamp 2024-03-27 11:04:34 UTC (01 08:21:18 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_fedora_38-gcc_13-bindist
timestamp 2024-03-27 11:04:31 UTC (01 08:21:21 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_12-gcc_13-static_O3
timestamp 2024-03-27 10:52:02 UTC (01 08:33:50 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_12-gcc_13-O3
timestamp 2024-03-27 10:48:40 UTC (01 08:37:13 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-gcc_13.1-static_O3
timestamp 2024-03-27 10:47:15 UTC (01 08:38:37 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-gcc_13.1-ndebug_O3
timestamp 2024-03-27 10:46:36 UTC (01 08:39:17 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-gcc_13.1-O3
timestamp 2024-03-27 10:44:45 UTC (01 08:41:07 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-gcc_13.1
timestamp 2024-03-27 10:44:39 UTC (01 08:41:13 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_12-gcc_13-ndebug_O3
timestamp 2024-03-27 10:42:30 UTC (01 08:43:23 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_fedora_37-gcc_12.2-bindist
timestamp 2024-03-27 10:41:39 UTC (01 08:44:13 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_12-gcc_13
timestamp 2024-03-27 10:41:23 UTC (01 08:44:29 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-linux-gnu
tgt config linux_debian_12-gcc_12-bindist
timestamp 2024-03-27 10:38:22 UTC (01 08:47:30 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_12-clang_15
timestamp 2024-03-27 10:28:11 UTC (01 08:57:42 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_12-clang_15_libc++
timestamp 2024-03-27 10:26:03 UTC (01 08:59:49 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_11-gcc_12
timestamp 2024-03-27 10:24:25 UTC (01 09:01:28 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_12-clang_16_libc++-static_O3
timestamp 2024-03-26 12:36:48 UTC (02 06:49:05 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_12-clang_16-static_O3
timestamp 2024-03-26 12:35:00 UTC (02 06:50:53 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_12-clang_16_libc++-O3
timestamp 2024-03-26 12:33:55 UTC (02 06:51:57 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_12-clang_16
timestamp 2024-03-26 12:33:23 UTC (02 06:52:30 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_12-clang_16-O3
timestamp 2024-03-26 12:32:53 UTC (02 06:53:00 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target aarch64-linux-gnu
tgt config linux_debian_12-clang_16_libc++
timestamp 2024-03-26 12:32:21 UTC (02 06:53:31 days ago)
result error (update) | log | rebuild
toolchain public-0.16.0
target x86_64-apple-darwin22.5.0
tgt config macos_13-clang_15.0-static_O3
timestamp 2024-03-26 03:37:53 UTC (02 15:47:59 days ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-apple-darwin22.5.0
tgt config macos_13-clang_15.0-O3
timestamp 2024-03-26 03:37:13 UTC (02 15:48:40 days ago)
result success | log | rebuild
toolchain public-0.16.0
target x86_64-apple-darwin22.5.0
tgt config macos_13-clang_15.0
timestamp 2024-03-26 03:36:35 UTC (02 15:49:18 days ago)
result success | log | rebuild
target x86_64-w64-mingw32
tgt config windows_10-gcc_12.2_mingw_w64
result excluded (builds but some tests fails, use at your own risks)
target x86_64-w64-mingw32
tgt config windows_10-gcc_12.2_mingw_w64-O2
result excluded (builds but some tests fails, use at your own risks)
target x86_64-w64-mingw32
tgt config windows_10-gcc_12.2_mingw_w64-static_O2
result excluded (builds but some tests fails, use at your own risks)