NSLog日志保存到本地

/* 保存日志 */
- (void)redirectNSLogToDocumentFolder{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *fileName =[NSString stringWithFormat:@"%@.log",@"log1"];//[NSDate date]];
    NSString *logFilePath = [documentsDirectory stringByAppendingPathComponent:fileName];
    freopen([logFilePath cStringUsingEncoding:NSASCIIStringEncoding],"a+",stderr);
}




- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
//保存输出 到 日志
    [self redirectNSLogToDocumentFolder];
...
}