🪵 minilog

Minimalistic logging library with threads and manual callstacks.

Features

• Easy to use (2 files, C-style interface)
• Multiple outputs (a text log file, an HTML log file, Android logcat, system console with colors)
• Thread-safe (write to log from multiple threads, set thread names)
• Cross-platform (Windows, Linux, OS X, Android)
• Callbacks (if you want to intercept formatted log messages)
• Custom time stamps
• C++17

Basic usage

#include "minilog/minilog.h"
...
minilog::initialize("log.txt", {});
minilog::log(minilog::Log, "Hello world!");
minilog::log(minilog::Log, "%s", "Hello again!");
minilog::log(minilog::Warning, "Warning!!!");
minilog::deinitialize();

Console output:

HTML log + manual callstack + multiple threads

All calls to log(), callstackPushProc(), callstackPopProc() are thread-safe. Furthermore, callstacks are per thread.

void testThread()
{
	minilog::initialize("log_thread.html", { .htmlLog = true });
	std::thread t([]()
	{
		minilog::threadNameSet("OtherThread");
		minilog::callstackPushProc("std::thread->");
		minilog::log(minilog::Log, "Hello from another thread!");
		minilog::log(minilog::Warning, "Warning from another thread!!!");
		minilog::callstackPopProc();
	});
	minilog::callstackPushProc("testThread()->");
	minilog::log(minilog::Log, "Hello world!");
	minilog::log(minilog::Warning, "Warning!!!");
	minilog::callstackPopProc();
	t.join();
	minilog::deinitialize();
}

If you want, you can use optional LLOGL(), LLOGW(), LLOGD() macros instead of calling minilog::log() directly.

HTML output:

You can also use the CallstackScope class to manage your callstack in RAII-style.

Intercept formatted messages

If you have a GameConsole class which can display messages within your in-game UI, you can intercept logs the following way:

minilog::LogCallback cb = { .userData = this };
cb.funcs[minilog::Log] = [](void* data, const char* msg) { reinterpret_cast<GameConsole*>(data)->Display(msg); };
cb.funcs[minilog::Warning] = [](void* data, const char* msg) { reinterpret_cast<GameConsole*>(data)->DisplayError(msg); };
cb.funcs[minilog::FatalError] = [](void* data, const char* msg) { reinterpret_cast<GameConsole*>(data)->DisplayError(msg); };
minilog::callbackAdd(cb);

All callback invocations are guarded by a mutex and will not happen concurrently (but may be invoked from multiple threads).