Read binary data from std::cin

std::cin is not opened with ios_binary. If you must use cin, then you need to reopen it, which isn't part of the standard.

Some ideas here: http://compgroups.net/comp.unix.programmer/How-can-I-reopen-std-cin-and-std-cout-in-binary-mode.

Once it's binary, you can use cin.read() to read bytes. If you know that in your system, there is no difference between text and binary (and you don't need to be portable), then you can just use read without worrying.

For windows, you can use the _setmode function in conjunction with cin.read(), as already mentioned.

_setmode(_fileno(stdin), _O_BINARY);
cin.read(...);

See solution source here: http://talmai-oliveira.blogspot.com/2011/06/reading-binary-files-from-cin.html

cin.read would store a fixed number of bytes, without any logic searching for delimiters of the type that @Jason mentioned.

However, there may still be translations active on the stream, such as CRLF -> NL, so it still isn't ideal for binary data.

On a Unix/POSIX system, you can use the cin.get() method to read byte-by-byte and save the data into a container like a std::vector<unsigned int>, or you can use cin.read() in order to read a fixed amount of bytes into a buffer. You could also use cin.peek() to check for any end-of-data-stream indicators.

Keep in mind to avoid using the operator>> overload for this type of operation ... using operator>> will cause breaks to occur whenever a delimiter character is observed, and it will also remove the delimiting character from the stream itself. This would include any binary values that are equivalent to a space, tab, etc. Thus the binary data your end up storing from std::cin using that method will not match the input binary stream byte-for-byte.