zlogger

Header-only, thread-safe, lightweight, stream-overloaded logger

Getting Started

Simply grab the header file zlogger.hpp from the include folder and include into your project 🚀🌟

Examples

To build the examples:

mkdir build && cd build
cmake ..
cmake --build . --config Release

Logging to console

zlogger logs to console by default.

LOG_TRACE << "testing, testing!"; /* should not appear by default */
LOG_INFO << "Hello there!";
LOG_INFO << "My name is " << " Timothy," << " and my age is: " << 25;
LOG_ERROR << "Oops, I made a mistake!";
LOG_WARN << "My hair is not doing great today with a spikiness index of " << 0.78283 << " , goodness!";

zlogger::set_level(zlogger::level::error);
LOG_WARN << "My hair still isn't that great!"; /* should not appear */
LOG_ERROR << "Mistake number 2!";
LOG_DEBUG << "Hi"; /* should not appear */

zlogger::set_level(zlogger::level::trace); /* everything should appear now */
LOG_TRACE << "Test test #2!"; 
LOG_DEBUG << "Debuggin'";
LOG_INFO << "INfo-in'";
LOG_WARN << "Warn-in'";
LOG_ERROR << "Kaboom";

The output may look something like:

[INFO][07/06/22 18:47:55][PID: 43136] Hello there!
[INFO][07/06/22 18:47:55][PID: 43136] My name is  Timothy, and my age is: 25
[ERROR][07/06/22 18:47:55][PID: 43136] Oops, I made a mistake!
[WARN][07/06/22 18:47:55][PID: 43136] My hair is not doing great today with a spikiness index of 0.78283 , goodness!
[ERROR][07/06/22 18:47:55][PID: 43136] Mistake number 2!
[TRACE][07/06/22 18:47:55][PID: 43136] Test test #2!
[DEBUG][07/06/22 18:47:55][PID: 43136] Debuggin'
[INFO][07/06/22 18:47:55][PID: 43136] INfo-in'
[WARN][07/06/22 18:47:55][PID: 43136] Warn-in'
[ERROR][07/06/22 18:47:55][PID: 43136] Kaboom

To explicitly log to console (or switch back to logging to console):

zlogger::set_output_stream(std::cout);

Logging to file

Simply change output stream and then log away 🚀

std::ofstream out_file_handle(LOGFILE_PATH);
if (out_file_handle.is_open()) {
    zlogger::set_output_stream(out_file_handle);
} else {
    throw std::runtime_error(std::string("Could not open ") + LOGFILE_PATH + " for writing");
}

LOG_TRACE << "testing, testing!"; /* should not appear by default */
LOG_INFO << "Hello there!";

Thread-safety

While zlogger cannot prevent race conditions between two threads trying to write to log at the same time, it will make sure that the messages are not interleaved in the output

#include <thread>
#include "zlogger.hpp"

void logging1() {
    LOG_TRACE << "testing, testing!";
    LOG_INFO << "Hello there!";
    LOG_INFO << "My name is " << " Timothy," << " and my age is: " << 25;
    LOG_ERROR << "Oops, I made a mistake!";
    LOG_WARN << "My hair is not doing great today with a spikiness index of " << 0.78283 << " , goodness!";
}

void logging2() {
    zlogger::set_level(zlogger::level::error);
    LOG_WARN << "My hair still isn't that great!";
    LOG_ERROR << "Mistake number 2!";
    LOG_DEBUG << "Hi"; 
}

void logging3() {
    zlogger::set_level(zlogger::level::trace);
    LOG_TRACE << "Test test #2!"; 
    LOG_DEBUG << "Debuggin'";
    LOG_INFO << "INfo-in'";
    LOG_WARN << "Warn-in'";
    LOG_ERROR << "Kaboom";
}

int main(int argc, char* argv[]) {
    std::thread t1{logging1}, t2{logging2}, t3{logging3};

    /* synchronize the threads, pauses until all 3 threads finish */
    t1.join();
    t2.join();
    t3.join();

    return EXIT_SUCCESS;
}

Possible output: