如何从字节读取信息[] [英] How to read information from a byte[]

问题描述

嗨 我需要有关如何从C ++中的byte []读取信息的帮助.我知道有关数组的标头信息，例如一次要读取多少位(例如4位为integer)和顺序.

谢谢

Hi I need help on how to read information from the byte[] in C++. I know the header information about the array like how many bits to be read at a time(for example 4 bits for integer )and the order.

Thanks

推荐答案

您的意思不大.我认为您在位和字节之间造成了混乱.我猜您想要从字节数组中提取数据.请注意，C ++中没有字节类型，可能是typedef(用于无符号字符).我也猜你在找什么，就像这样:

You''re not making too much sense. I think you make a confusion between bits and bytes. I guess what you want is to extract data from an array of bytes. Notice there is no byte type in C++, that is probably a typedef (for unsigned char). I also guess what you are looking for is something like this:

int extract_int(unsigned char[] array, size_t offset)
{
    int n = 0;
    memcpy(&n, array + offset, sizeof(n));
    return n;
}

但是，这不能解决某些问题:
-字节序:小字节序与大字节序，以及如何将数据存储在数组中；我的样本假设它是小端字节数
-验证:您需要做一些额外的验证，例如偏移量+提取的数据类型的大小不超出数组的范围.

However, this does not address some issues:
- the endianess: little endian vs. big endian, and how your data is stored in the array; my sample assume it''s little endian
- validation: you need to do some extra validation, like that offset + sizeof the extracted data type is not beyond the boundaries of the array.

您已编辑了此问题，但未添加任何问题更多信息.如果要从C ++中读取数据块(从何处读取)，请查看 fstream fstream [ ^ ]类，或 fread() [

You have edited this question, but not added any more information. If you want to read blocks of data (from where?) in C++ then look at the fstream[^] class, or the fread()[^] CRT function.

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