Easylogging + + log Library

I recently learned about this powerful log Library , It's really fragrant .

brief introduction

Easylogging++ Is used for C++ Single header efficient log library for applications . It's very powerful , Highly scalable and can be configured according to user requirements . It provides the ability to write your own receiver （ Through the called The characteristics of LogDispatchCallback）. The library is currently github And hundreds of open source projects on other open source source control and management sites .

Reference resources

GitHub
https://github.com/amrayn/easyloggingpp
https://www.cnblogs.com/bokeyuan-dlam/articles/7635003.html

Use configuration

I recommend using the configuration log file for configuration . Create a new one easylogging.conf file
Configuration interpretation ：

* GLOBAL:  
    ENABLED                 =   true
    TO_FILE                 =   true  
    TO_STANDARD_OUTPUT      =   true  
    FORMAT                  =   "%datetime %level [%fbase|%line] %msg"  
    FILENAME                =   "C:\\logs\\%datetime{%Y%M%d}.log"  
    MILLISECONDS_WIDTH      =   3  
    PERFORMANCE_TRACKING    =   false  
    MAX_LOG_FILE_SIZE       =   20048576  
    LOG_FLUSH_THRESHOLD     =   0  

* TRACE:  
* DEBUG:  
* FATAL:  
* ERROR:  
* WARNING:  
* INFO:  
* VERBOSE:  

When the project is initialized, just load the configuration file .

#include "easylogging++.h"
INITIALIZE_EASYLOGGINGPP
void initLog()
{
    
	// The flag must be set  LoggingFlag::StrictLogFileSizeCheck
	// otherwise ,  In profile MAX_LOG_FILE_SIZE = 20048576  Don't take effect 
	// Mode one ： Load local conf The way 
	el::Loggers::addFlag(el::LoggingFlag::StrictLogFileSizeCheck);
	// Configuration file path address 
	el::Configurations conf("C:\\esaylogging.conf");
	// One can be set separately logger Configuration of  
	//el::Loggers::reconfigureLogger("default", conf);
	///  You can also set all logger Configuration of  
	el::Loggers::reconfigureAllLoggers(conf);

	// Mode two ： Load default configuration 
	el::Configurations conf;
	conf.setToDefault();
	conf.setGlobally(el::ConfigurationType::Format, "%datetime %level [%fbase|%line] %msg");
	conf.setGlobally(el::ConfigurationType::Filename, path+"\\%datetime{%Y%M%d}.log");
	conf.setGlobally(el::ConfigurationType::Enabled, "true");
	conf.setGlobally(el::ConfigurationType::ToFile, "true");
	conf.setGlobally(el::ConfigurationType::ToStandardOutput, "true");
	
	el::Loggers::reconfigureAllLoggers(conf);	
}


int main(int argc, char *argv[])
{
    
	initLog();

	LOG(INFO) << "My First Easylog!";

	return 0;
}

Finally, you can use the log happily .

effect

Be able to locate the output log of your code . Very fragrant, very fragrant .

Disable default generated myeasylog.log file

stay easylogging++.cc Add the following macro definition
#define ELPP_NO_DEFAULT_LOG_FILE

	LINFO <<  Class name ;

main Function can be used in LINFO Like other built-in data types, it outputs myClass, Will output log as follows ：
1 4:32:47.031 INFO MyClass name is Awesome class
If you want to output STL Of string,wstring Class and container ：vector,list,map,set etc. , Then just define the macro ：
#define _ELPP_STL_LOGGING
If you want to support QT Class output of Library , You need to define a macro ：
#define _ELPP_QT_LOGGING