日志程序

#ifndef _LOGGER_H_#define _LOGGER_H_#include <sstream>class Logger{public:    typedef enum    {        TRACE,        DEBUG,        INFO,        WARN,        ERROR,        FATAL,        LOGLEVEL_COUNT    }LogLevel;    Logger(const char *file, int line);    Logger(const char *file, int line, LogLevel level);    Logger(const char *file, int line, bool isAbort);    ~Logger();    std::ostream& Stream();        static LogLevel GetLevel();    static void SetLevel(LogLevel level);    static void SetHandle(int fd);    static LogLevel _s_level;    static int _s_fd;    private:    void InitMsgHead(const char *file, int line, LogLevel level = TRACE);    private:    LogLevel _level;    int _fd;    std::ostringstream _stream;};#define LOG_TRACE if (Logger::GetLevel() <= Logger::TRACE) \        Logger(__FILE__, __LINE__, Logger::TRACE).Stream()#define LOG_DEBUG if (Logger::GetLevel() <= Logger::DEBUG) \        Logger(__FILE__, __LINE__, Logger::DEBUG).Stream()#define LOG_INFO if (Logger::GetLevel() <= Logger::INFO) \        Logger(__FILE__, __LINE__).Stream()#define LOG_WARN Logger(__FILE__, __LINE__, Logger::WARN).Stream()#define LOG_ERROR Logger(__FILE__, __LINE__, Logger::ERROR).Stream()#define LOG_FATAL Logger(__FILE__, __LINE__, Logger::FATAL).Stream()#define LOG_SYSERR Logger(__FILE__, __LINE__, false).Stream()#define LOG_SYSFATAL Logger(__FILE__, __LINE__, true).Stream()#endif // _LOGGER_H_

#include "Logger.h"#include <stdio.h>#include <stdlib.h>#include <string.h>#include <time.h>#include <sstream>/// for test#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>Logger::LogLevel Logger::_s_level = Logger::TRACE;int Logger::_s_fd = 1;Logger::Logger(const char *file, int line){    InitMsgHead(file, line);}Logger::Logger(const char *file, int line, LogLevel level){    InitMsgHead(file, line, level);}Logger::Logger(const char *file, int line, bool isAbort){    LogLevel level = (isAbort?FATAL:ERROR);    InitMsgHead(file, line, level);}Logger::~Logger(){    std::string buf(_stream.str());    ssize_t num = ::write(_s_fd, buf.data(), buf.size());    if (_level == FATAL)    {        abort();    }}std::ostream& Logger::Stream(){    return _stream;}Logger::LogLevel Logger::GetLevel(){    return _s_level;}void Logger::SetLevel(LogLevel level){    _s_level = level;}void Logger::SetHandle(int fd){    _s_fd = fd;}void Logger::InitMsgHead(const char *file, int line, LogLevel level){    const char *logLevel[LOGLEVEL_COUNT] =        {"TRACE", "DEBUG", "INFO", "WARN", "ERROR", "FATAL"};    char msgHead[128] = {0};    time_t curtime = time(NULL);    struct tm *gm = localtime(&curtime);    const char *pstr = strrchr(file, '/');    const char *name = ((pstr!=NULL) ? pstr+1 : file);    _level = level;        snprintf(msgHead, sizeof(msgHead), "[%s\t%04d-%02d-%02d %02d:%02d:%02d %s:%03d]",             logLevel[_level], gm->tm_year+1900, gm->tm_mon+1, gm->tm_mday,             gm->tm_hour, gm->tm_min, gm->tm_sec, name, line);    _stream << msgHead;}/////////////////////////test pass//////////////////////////////int main(void){    /*int fd = open("./log.txt", O_RDWR|O_CREAT|O_APPEND);    if (-1 == fd)    {        printf("open error\n");    }    Logger::SetHandle(fd);    Logger::SetLevel(Logger::ERROR);    */    LOG_TRACE << "this is trace\n";    printf("\n");    LOG_WARN << "this is warning\n";    printf("\n");    LOG_ERROR << "this is error\n";    printf("\n");    LOG_SYSERR << "this is system\n";    printf("\n");    //LOG_SYSFATAL << "this is sysfatal\n";    //printf("\n");    LOG_WARN << "this is last\n";    getchar();        return 0;}//*////////////////////////////////////////////////////////////////

日志监视，当日志文件大小超过1M的时候关闭文件改名保存起来，用相同的路径名重新创建一个日志文件写入日志

int InitLog(){    int fd = open(AUDIT_LOG_FILE, O_RDWR|O_CREAT|O_APPEND);    if (-1 == fd)    {        return -1;    }    Logger::SetHandle(fd);    Logger::SetLevel(Logger::DEBUG);    Logger::SetProcname("hello");    return 0;}/** * 监视日志文件 * @param void * @return void */void WatchAuditLog(){    char mvCmd[256] = {0};    struct stat logStat;    if (fstat(Logger::_s_fd, &logStat))    {        return;    }    if (logStat.st_size > (1024*1024))    {        close(Logger::_s_fd);        snprintf(mvCmd, sizeof(mvCmd), "mv %s %s", AUDIT_LOG_FILE, AUDIT_LOG_FILE_BAK);        if (system(mvCmd) < 0)        {            return;        }        InitLog();    }}