iOS日志本地化--日志重定向

写在前面

本文主要是给读者分享技术的，如何保存能控制台输出的log，以便于查找程序本身出现的问题。

我们该如何做

首先

我们要判断，是不是模拟器

#if !(TARGET_IPHONE_SIMULATOR)//真机    //连接xcode时可以从监视器中看日志 没连接时Log日志会输出到文件中，    [self redirectNSLogToDocumentFolder];    NSLog(@"真机");#else//模拟器    NSLog(@"模拟器");#endif

其次

我们还要接着判断是不是真机连接了Xcode，然后才开始进行日志本地化文件的生成

- (void)redirectNSLogToDocumentFolder{    //如果已经连接Xcode调试则不输出到文件    if(isatty(STDOUT_FILENO)) {        return;    }    UIDevice *device = [UIDevice currentDevice];    if([[device model] hasSuffix:@"Simulator"]){ //在模拟器不保存到文件中        return;    }    //将NSlog打印信息保存到Document目录下的Log文件夹下    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    NSString *logDirectory = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"Log"];    NSFileManager *fileManager = [NSFileManager defaultManager];    BOOL fileExists = [fileManager fileExistsAtPath:logDirectory];    if (!fileExists) {        [fileManager createDirectoryAtPath:logDirectory  withIntermediateDirectories:YES attributes:nil error:nil];    }    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];    [formatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"zh_CN"]];    [formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"]; //每次启动后都保存一个新的日志文件中    NSString *dateStr = [formatter stringFromDate:[NSDate date]];    self.filepath = [logDirectory stringByAppendingFormat:@"/%@.log",dateStr];    // 将log输入到文件    freopen([self.filepath cStringUsingEncoding:NSASCIIStringEncoding], "a+", stdout);    freopen([self.filepath cStringUsingEncoding:NSASCIIStringEncoding], "a+", stderr);    //未捕获的Objective-C异常日志    NSSetUncaughtExceptionHandler (&UncaughtExceptionHandler);}

最后

这是一个报错的异常信息，也就是我们所说的崩溃信息

void UncaughtExceptionHandler(NSException* exception){    NSString* name = [ exception name ];    NSString* reason = [ exception reason ];    NSArray* symbols = [ exception callStackSymbols ]; // 异常发生时的调用栈    NSMutableString* strSymbols = [ [ NSMutableString alloc ] init ]; //将调用栈拼成输出日志的字符串    for ( NSString* item in symbols )    {        [ strSymbols appendString: item ];        [ strSymbols appendString: @"\r\n" ];    }    //将crash日志保存到Document目录下的Log文件夹下    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    NSString *logDirectory = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"Log"];    NSFileManager *fileManager = [NSFileManager defaultManager];    if (![fileManager fileExistsAtPath:logDirectory]) {        [fileManager createDirectoryAtPath:logDirectory  withIntermediateDirectories:YES attributes:nil error:nil];    }    //NSString *logFilePath = [logDirectory stringByAppendingPathComponent:@"UncaughtException.log"];    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];    [formatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"zh_CN"]];    [formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];    AppDelegate *app = [UIApplication sharedApplication].delegate;    NSString *dateStr = [formatter stringFromDate:app.date];    NSString *crashString = [NSString stringWithFormat:@"<- %@ ->[ Uncaught Exception ]\r\nName: %@, Reason: %@\r\n[ Fe Symbols Start ]\r\n%@[ Fe Symbols End ]\r\n\r\n", dateStr, name, reason, strSymbols];    //把错误日志写到文件中    if (![fileManager fileExistsAtPath:app.filepath]) {        [crashString writeToFile:app.filepath atomically:YES encoding:NSUTF8StringEncoding error:nil];    }else{        NSFileHandle *outFile = [NSFileHandle fileHandleForWritingAtPath:app.filepath];        [outFile seekToEndOfFile];        [outFile writeData:[crashString dataUsingEncoding:NSUTF8StringEncoding]];        [outFile closeFile];    }    //把错误日志发送到邮箱    NSString *urlStr = [NSString stringWithFormat:@"mailto://邮箱账号?subject=bug报告&body=感谢您的配合!错误详情:%@",crashString ];    NSURL *url = [NSURL URLWithString:[urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];    [[UIApplication sharedApplication] openURL:url];}

使用

在AppDelegate的这个方法中编写如下代码

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {#if !(TARGET_IPHONE_SIMULATOR)//真机    //连接xcode时可以从监视器中看日志 没连接时Log日志会输出到文件中，    [self redirectNSLogToDocumentFolder];    NSLog(@"真机");#else//模拟器    NSLog(@"模拟器");#endifreturn YES;}