https://blog.cnbluebox.com/blog/2014/06/06/shi-yong-cocoalumberjackhe-xcodecolorsshi-xian-fen-ji-loghe-kong-zhi-tai-yan-se/

1, log输出到不同的地方
2，log定义级别，设置不同级别的输出控制开关
3，使用不同的级别日志输出接口
4，格式化输出内容
5，定时器输出日志
6，日志文件管理：打包，自动拆分成多个日志文件

- (NSString *)formatLogMessage:(DDLogMessage *)logMessage {
    NSString *logLevelStr = @"";
    switch (logMessage.flag) {
        case DDLogFlagError:
            logLevelStr = @"[Error] > ";
            break;
        case DDLogFlagWarning:
            logLevelStr = @"[Warning] > ";
            break;
        case DDLogFlagInfo:
            logLevelStr = @"[Info] > ";
            break;
        case DDLogFlagDebug:
            logLevelStr = @"[Debug] > ";
            break;
        case DDLogFlagVerbose:
            logLevelStr = @"[Verbose] > ";
            break;
        default:
            break;
    }
    NSString *formatStr = [NSString stringWithFormat:@"%@:  %@, %@, %@ line[%ld], %@", logLevelStr, logMessage.timestamp, logMessage.threadName, logMessage.function, logMessage.line, logMessage.message];
    return formatStr;
}


    // 设置输出到文件
    DDFileLogger *fileLogger = [[DDFileLogger alloc] init];
    // 输出文件分割规则
    fileLogger.rollingFrequency = 60 * 60 * 24; // 24 hour rolling
    // 最多log文件数量。过期的文件被替换
    fileLogger.logFileManager.maximumNumberOfLogFiles = 7;
    [fileLogger setLogFormatter:[[MyDDLogFormatter alloc] init]];
    [DDLog addLogger:fileLogger];
    
    
    // 设置输出到控制台
    [[DDTTYLogger sharedInstance] setColorsEnabled:YES];
    [[DDTTYLogger sharedInstance] setForegroundColor:DDMakeColor(0, 0, 255) backgroundColor:DDMakeColor(0, 0, 0) forFlag:DDLogFlagDebug];
    [[DDTTYLogger sharedInstance] setLogFormatter:[[MyDDLogFormatter alloc] init]];
    [DDLog addLogger:[DDTTYLogger sharedInstance]];
    
    
    
    
    
    DDLogDebug(@"asdf:%@",@"asdf");
    DDLogInfo(@"asdf:%@",@"asdf");