ClarkMcGrew/simple-cpp-logger

A simple header-only library written in C++ which provide logger features

Description

This simple header-only library written in C++ provides logging features with handy options. Because it's written as a header-only library, you can easily add it to your current project. A cmake example file is shipped within this repository.

Features

• 7 different levels of logging severity: Fatal, Error, Alert, Warning, Info, Debug and Trace.
• Both "std::cout <<" and "printf()" call-style are available with the same names.
• Ajustable prefix can display the Time, Severity, Current Filename, Current Line Number, Current Thread ID and even a custom header string set by the user.
• Ability to mute prints based on their severity.
• Option to disable colors on the prefix.
• Static members (user options) of this header class are globally settable with preprocessor macros (see cmake's add_definitions calls).
• In-string "\n" char are recognised and the prefix is automatically reprinted.

Showcase

Here is a screenshot of the first output lines you get while running the example.

If you want to see all the features embedded in the example, feel free to build and run it yourself:

git clone https://github.com/nadrino/simple-cpp-logger.git
mkdir simple-cpp-logger/build
cd simple-cpp-logger/build
cmake ../
make
./LoggerExample

Requirements

• C++11 or higher is required to use this logger.

Getting Setup

You can add simple-cpp-logger to your existing project as a submodule for example. In this guide we assume that your project is using CMake. In your CMakeLists.txt, add the following lines:

include_directories(path/to/simple-cpp-logger/include)

Preprocessor variables are defined in Logger.h, and can be changed by adding the following lines to CMakeLists.txt:

add_definitions( -D LOGGER_MAX_LOG_LEVEL_PRINTED=6 )
add_definitions( -D LOGGER_PREFIX_LEVEL=2 )
add_definitions( -D LOGGER_ENABLE_COLORS=1 )
add_definitions( -D LOGGER_ENABLE_COLORS_ON_USER_HEADER=0 )

Now you can include the header in your source file:

#include <Logger.h>

Then you're all set!

Implementation Guidelines

Here are simple example lines of implementation. If you want to know more about the available features, you can refer to "example/main.cpp".

Let's print a simple line:

LogInfo << "My very important message" << std::endl;

You have just printed a line on screen with the tag "Info". LogInfo is actually a preprocessor macros which automatically passes the filename and the line number from where it's called.

It exists different variants of this same call: LogFatal, LogError, LogAlert, LogWarning, LogInfo, LogDebug and LogTrace. Each of these will display their proper verbosity tag.

These calls can as well be made in the style of the C function printf():

LogInfo("The variable is: %i", my_int);

Few user parameters can be access from the Logger class. For example let's change the highest printed log level:

Logger::setMaxLogLevel(Logger::LogLevel::INFO);

From this moment, all following Log calls will be printed if their associated log level is lower than INFO. This means that LogFatal, LogError, LogAlert, LogWarning and LogInfo will be printed, but LogDebug and LogTrace will be muted.

Keep in mind that every parameter you set this way will be only be applied for the current source file. For a global effect, you need to set the associated preprocessor variables accordingly (cf. CMakeLists.txt).