下面是前段时间做项目用到的一个输出LOG日志的代码，每个文件最多记录10W行，超过10W行，将当前日志文件重命名，重新再打开。直接看代码吧，很简单！

int InitTCpRtpLog()
{

    char log[256];

    mkdir(TCP_RTP_LOG_PATH, 0755);

    snprintf(log, sizeof(log), "%s/%s", TCP_RTP_LOG_PATH, TCP_RTP_LOG_FILE);
    vTcpRtpLogHandle = fopen((char*)log, "a");
    if (vTcpRtpLogHandle){
            PrintMsgTrace("###%s(),creat log file %s sucessfull!\n",__FUNCTION__, log);

        return 0;
    }else{
        PrintMsgTrace("###$s(), Fail openning event log file (errno=%s)\n", __FUNCTION__, strerror(errno));

        return  - 1;
    }
}
static int _rebuildTcpRtpLogFiles()
{

    char tmp[256];
    char tmp2[256];
    char date[128];
    time_t now;
    struct tm ptm;
    

    if (vTcpRtpLogHandle)
    {
        fclose(vTcpRtpLogHandle);
        time(&now);
        localtime_r(&now,&ptm);
        strftime((char *)date, 128, "_%F_%T", &ptm);

        snprintf(tmp, sizeof(tmp), "%s/%s", TCP_RTP_LOG_PATH, TCP_RTP_LOG_FILE);
        snprintf(tmp2, sizeof(tmp2), "%s_%s.log", tmp,date);

        remove(tmp2);
        rename(tmp, tmp2);

        vTcpRtpLogHandle = fopen((char*)tmp, "a");
    }

    return 1;
}


void LogTcpRtp(char *p_fmt, ...)
{
    char date[256];
    time_t now;
    struct tm ptm;
    va_list ap;


    if (!vTcpRtpLogHandle){
        return;
    }

    pthread_mutex_lock(&_vTcpRtpLogMutex);

    time(&now);                   // Gets the system time

    if (localtime_r(&now, &ptm))
    {
        strftime(date, sizeof (date), "%F %T", &ptm);
        fprintf(vTcpRtpLogHandle, "[ %s ]:", date);

        va_start(ap, p_fmt);
        vfprintf(vTcpRtpLogHandle, p_fmt, ap);
        va_end(ap);

        fflush(vTcpRtpLogHandle);

        _vCurTcpRtpLogNum++;
        if (_vCurTcpRtpLogNum > MAX_RTP_TCP_NUMBER){
            _rebuildTcpRtpLogFiles();
            _vCurTcpRtpLogNum = 0;
        }
    }

    pthread_mutex_unlock(&_vTcpRtpLogMutex);
}