C++ 实现日志记录到文件-优快云博客

本文链接：https://blog.youkuaiyun.com/stonehuzhan/article/details/2472241

这是一个C++的日志记录类实现，用于将不同级别的日志信息（ERROR、WARN、INFO、DEBUG）写入文件。类FLOG包含初始化、设置日志级别和输出到文件的功能，并具备文件大小限制，超过限制时会创建新的日志文件。

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/************filelog.h*****************************************************************************************/

#if !defined _FILE_FLOG_H
#define _FILE_FLOG_H
/*
*日志写入文件，
*
*
*/

#include <iostream>
#include <ios>
#include <time.h>
#include <fstream>
#include <stdio.h>
#include <stdarg.h>
#include <string>
#include <sstream>
#include <errno.h>
#include <cutil.h>
#include <map>

using namespace std;
using namespace CPPSocket;

namespace CPPSocket
{
class FLOG{
public:
   typedef enum RANK
   {
   ERROR = 0,
   WARN = 1,
   INFO = 2,
   DEBUG = 3
   }LOGRANK;

public:
  FLOG();
  ~FLOG();

  void init(map<string,string>& cfg);
  void init(string filename,LOGRANK rank=INFO,bool m_isBuf=false);
      FLOG& getTime(LOGRANK rank);

  template<class T> friend FLOG& operator<<(FLOG& out,T i)
  {
   if( out.m_rank <= out.m_initRank )
    out.m_os<<i;
   return out;
   }

friend FLOG& operator<<(FLOG& out,LOGRANK rank) //设置日志级别
  {
   out.m_rank = rank;
   return out;
   }

  friend FLOG& operator<<(FLOG& out,FLOG& lout)
  {
   return out;
  }

  friend FLOG& operator<<(FLOG& out,ostream& (*fendl)(ostream&))
  {
   if( out.m_rank <= out.m_initRank ){
    out.openlog();
    if(out.m_fileOpen){
     out.m_os<<"/n";
     out.m_logfile<<out.m_os.str();
     if(!out.m_isBuf) out.m_logfile<<flush;
    }else cout<<out.m_os.str()<<endl;
          out.m_os.str(""); //清空缓冲区
        }
        out.m_rank = FLOG::LOG_INFO; //恢复日志默认级别
        return out;
  }

private:
  FLOG& operator=(FLOG& log);
  FLOG(FLOG& log);
   void openlog();
private:
  string m_logname;
    string m_cur_logname;
    ofstream m_logfile;
    stringstream m_os;
    bool m_fileOpen;
  LOGRANK m_rank;
  LOGRANK m_initRank;
  bool m_isBuf;
public:
  static const LOGRANK LOG_ERROR = ERROR;
  static const LOGRANK LOG_WARN = WARN;
  static const LOGRANK LOG_INFO = INFO;
  static const LOGRANK LOG_DEBUG = DEBUG;
};

namespace FILELOG
{
    typedef FLOG LOG;
    extern FLOG mlog;
}

}

using namespace CPPSocket::FILELOG;

#endif

/*******************************************filelog.cpp*****************************************/

#include "filelog.h"
#include <sstream>

using namespace CPPSocket;

namespace CPPSocket
{
namespace FILELOG
{
    FLOG mlog;
}

FLOG::FLOG():m_fileOpen(false),m_rank(INFO),m_initRank(INFO),m_isBuf(false)
{

}

FLOG::~FLOG()
{
if(m_fileOpen){
  cout<<"[close file]"<<m_cur_logname<<endl;
  m_logfile.close();
  m_fileOpen = false;
}
}

void FLOG::init(string filename,LOGRANK rank,bool isBuf)
{
cout<<"into FLOG::init"<<endl;
m_initRank = rank;
m_isBuf = isBuf;
if(filename.size()==0) return;
m_logname = filename;
m_cur_logname = m_logname + T::getTime();
cout<<"[log file name]"<<m_cur_logname<<endl;
m_logfile.open(m_cur_logname.c_str(),ios::out|ios::app);
if(!m_logfile){
  m_fileOpen = false;
  return;
}
cout<<m_cur_logname<<"open sucess."<<endl;
m_fileOpen = true;
}

void FLOG:: init(map<string,string>& cfg)
{
string fname = "";
LOGRANK rank = INFO;
bool isBuf = false;
map<string,string>::iterator it = cfg.find("FILE");
if(it != cfg.end()) fname = it->second;
it = cfg.find("RANK");
if(it != cfg.end()){
        if("ERROR" == it->second)      rank = LOG::LOG_ERROR;
        else if("WARN" == it->second) rank = LOG::LOG_WARN;
        else if("INFO" == it->second) rank = LOG::LOG_INFO;
        else if("DEBUG" == it->second) rank = LOG::LOG_DEBUG;
}
it = cfg.find("ISBUF");
if(it != cfg.end()){
  if("TRUE" == it->second)       isBuf = true;
      else if("FALSE" == it->second) isBuf = false;
    }
init(fname,rank,isBuf);
}

void FLOG::openlog()
{
if(!m_fileOpen) return;
if(1792*1024*1024 < m_logfile.tellp()){ // FLOG文件不超过1.8GB
  m_logfile.close();
  m_cur_logname = m_logname + T::getTime();
  m_logfile.open(m_cur_logname.c_str(),ios::out|ios::app);
   if(m_logfile.fail()) m_fileOpen = false;
   else m_fileOpen = true;
}
}

FLOG& FLOG:: getTime(LOGRANK rank)
{
m_rank = rank;

if( m_rank <= m_initRank )
  m_os<<T::getTime1();

return *this;
}

}

/*******************************************************test.cpp*********************/

#include<iostream>

#incldue "filelog.h"

using namesapce std;

using namesapce CPPSocket;

int main(int argc,char * argv[])
{
mlog.init("/tmp/log.log",LOG::LOG_ERROR);
mlog<<LOG::LOG_ERROR<<T::getTime1()<<"test LOG_ERROR"<<endl;

mlog.getTime(LOG::LOG_ERROR)<<"test LOG_ERROR"<<endl;
mlog<<LOG::LOG_WARN<<T::getTime1()<<"test LOG_WARN"<<endl;
mlog<<LOG::LOG_INFO<<T::getTime1()<<"test LOG_INFO"<<endl;
mlog<<LOG::LOG_DEBUG<<T::getTime1()<<"test LOG_DEBUG"<<endl;
mlog<<LOG::LOG_ERROR<<T::getTime1()<<"test end---------"<<endl;
return 0;
}