iOS APP日志写入文件（日志收集）

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOption
    //日志收集(日志会被拦截，开发的时候注掉)
    [self redirectNSlogToDocumentFolder];

方法实现

#pragma mark - 日志收集
- (void)redirectNSlogToDocumentFolder
{
    NSString *documentDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    
    NSDateFormatter *dateformat = [[NSDateFormatter  alloc]init];
    [dateformat setDateFormat:@"yyyy-MM-dd-HH-mm-ss"];
    NSString *fileName = [NSString stringWithFormat:@"LOG-%@.txt",[dateformat stringFromDate:[NSDate date]]];
    NSString *logFilePath = [documentDirectory stringByAppendingPathComponent:fileName];
    
    // 先删除已经存在的文件
    NSFileManager *defaultManager = [NSFileManager defaultManager];
    [defaultManager removeItemAtPath:logFilePath error:nil];
    
    // 将log输入到文件
    freopen([logFilePath cStringUsingEncoding:NSASCIIStringEncoding], "a+", stdout);
    
    freopen([logFilePath cStringUsingEncoding:NSASCIIStringEncoding], "a+", stderr);
}

在需要进行收集的时候将文件上传到服务器