Converting a String to Binary

[Knuckles53]

I need some help, my C++ coding skills are a little old and rusty.

I need to read in a series of 8-bits stored in a text file. How do I read in these values and get the proper result?

For example, the file looks like this:

01101011 00101011 010101101 ....

That is saved in a .txt file as ASCII characters, but I need to manipulate them as bytes. Can anyone provide any help? Thanks for your time.

[RRick]

Actually, don't worry about the binary stuff, your file is in ascii which is just what C++ and the IO objects like. 8 bit bytes is the format that ascii uses. Usually, a .txt file of ascii characters is viewable with an editor (i.e. vi or notepad).

Take a look further down these postings for a tutorial on C++ IO. Open the file, read lines of text into a string and (probably) print it out to the screen. Loop until you've read everything.

Cheers

[Knuckles53]

Thanks but that's not what I mean. The file is a series of 1's and 0's. If I read it in as an int I get a base 10 number with any leading zeros dropped. So 0011 would be eleven, not binary 3. If I read it in as a series of chars I get ASCII 48 and 49. What I need is to be able to read in the eight binary digits and save them so that I can perform a series of bit-wise XOR's, AND's, etc.

Can anyone provide help? I guess I could brute force it but there has to be a more elegant way.

Thanks

[Ganon11]

The only way I could think of is storing these integers in a series of int arrays of size 8, then processing them that way. I know there's a way to read binary files, but I'm not sure...something like ios::bin comes to mind...

[horace1]

If the binary data is 0 and 1 characters you could read the 0's and 1's as sequences of 8 bit values converting them to ints, e.g. to read one byte

#include <iostream>
#include <iomanip>
using namespace std;
 
int main()
{
    int data=0;
    char bit;
    for(int i=0;i<8;i++)
      {
       // read a 0 or 1 skipping whitespace
       cin >> ws >> bit;
       // shift existing data one left and add current bit value
       data = (data << 1) + (bit - '0');
       }
      cout << "data " << hex << data << endl;
      system("pause");
}
 

when run gives
00000101
data 5
Press any key to continue . . .