object-c中对文件操作

NSString *filePath = @"/Users/scjy/hello/iphone.txt";
        
        NSFileHandle *handle=[NSFileHandle fileHandleForUpdatingAtPath:filePath];//准备更新
        
        [handle seekToEndOfFile];//读取到文件末尾
        
        NSString *addString=@"尚承教育";
        
        NSData *data=[addString dataUsingEncoding:NSUTF8StringEncoding];//将字符串转换成data数据
        
        [handle writeData:data];//写入数据
        
        [handle closeFile];//关闭文件
        
        
        //读取
        NSFileHandle *handle1 = [NSFileHandle fileHandleForReadingAtPath:filePath];
        NSData *data1 = [handle1 readDataToEndOfFile];
        NSString *readString=[[NSString alloc]initWithData:data1 encoding:NSUTF8StringEncoding];
        NSLog(@"%@",readString);

//复制文件
        
        
        //找到原来的文件路径
        NSString *old_filePath = @"/Users/scjy/hello/iphone.txt";
        
        //指定新的文件路径（文件不存在）
        NSString *new_filePath = @"/Users/scjy/hello/ios.txt";

        //创建文件管理器，为创建新的文件做准备
        NSFileManager *fileManager=[NSFileManager defaultManager];
        
        //创建新的文件（此时文件中无数据）
        BOOL isSuccess=[fileManager createFileAtPath:new_filePath contents:nil attributes:nil];
        if (isSuccess) {
            NSLog(@"创建成功");
            
            //1.读取原文件中的数据：fileHandleForReadingAtPath
            NSFileHandle *old_handle=[NSFileHandle fileHandleForReadingAtPath:old_filePath];
            NSData *old_data=[old_handle readDataToEndOfFile];
            
            //2.将原文件中获取的数据写入新的文件：fileHandleForWritingAtPath
            NSFileHandle *new_handle=[NSFileHandle fileHandleForWritingAtPath:new_filePath];
            [new_handle writeData:old_data];
            
            [old_handle closeFile];
            [new_handle closeFile];
            
        }
        else
        {
            NSLog(@"创建失败");
        }