gabime/spdlog

spdlog is a fast logging library for C++ programs. Logging means recording messages about what your program is doing, errors, warnings, debug info, so you can understand its behavior or diagnose problems. spdlog focuses on doing this with minimal impact on your program's speed. The library is "header-only," meaning you use it simply by copying its source files into your project and including them, no separate compilation or installation step is required, though package managers for various operating systems are also supported. Once included, you create named loggers and call methods like info(), warn(), error(), or debug() to record messages. You can direct those messages to the console, to plain files, to rotating log files (which automatically start a new file once a size limit is reached), to daily log files, or to the system log. Formatting is flexible, with support for rich text patterns and colored console output. A key feature is asynchronous logging: by enabling async mode, log writes are handed off to a background queue instead of blocking your program, keeping things fast. Log severity levels can be filtered at runtime or at compile time, so you can turn verbose debug output on or off without changing code. Multiple threads can share a single logger safely. The code examples in the README demonstrate creating console loggers, file loggers, rotating loggers, and custom format patterns. spdlog is written in C++ and requires a C++11 compiler. It is used when building any C++ application, games, servers, tools, where recording program activity quickly and reliably matters.