trouble with bit streams

[dendog]

I have a few questions about working with bit streams.

how do i output a bit stream
how do i store a bit stream
how do i read in a bit stream

i want to print out and take in and store bits as a bit stream and not just characters that are either one or zero
How would i do this

Thank you very much for trying to help me

 

[StukA]

Where are you trying to input/output this from? The nature of the output will really decide what you want to do. If, for example, you want to send a stream of bits to a serial port, the best bet would be to combine them in sets of 8 and send write that value. Other output forms may require different methodology, but writing out bytes is almost certainly going to be involved.

 

[DavesTips]

Certainly the easisest way of handling bits is with the STL bitset class. The following code sets up an array of 8-bit bitsets, writes it to a file, reads it in again and prints it out (as character 0,1) to stdout.

#include <iostream>
#include <vector>
#include <bitset>
#include <fstream>

using namespace std;

typedef vector<bitset<8> > tvbs8; // Aarray of 1 byte bitsets

int main(int argc, char* argv[])
{
tvbs8 vbs8(5);
tvbs8::iterator ivbs8;
bool b = false;
int i,j;
unsigned long ul;

// Create bitset setting alternate bits in each byte
for (i = 0; i<vbs8.size(); i++)
{
for (j = 0; j<8; j++)
{
vbs8[j] = b = !b; // Set bit j in byte i alternately
}
}

// Print out our bitset array as char 0,1
for (ivbs8 = vbs8.begin(); ivbs8!=vbs8.end(); ivbs8++) cout << *ivbs8 << endl;

// Write array to binary file
ofstream ofs(&quot;C:\\bitset.bin&quot;,ios_base::binary);
for (ivbs8 = vbs8.begin(); ivbs8!=vbs8.end(); ivbs8++) ofs << (unsigned char)(*ivbs8).to_ulong();
ofs.close();

// Read binary file back into a new bitset array
tvbs8 vbs8in;
ifstream ifs(&quot;C:\\bitset.bin&quot;,ios_base::binary);
while(ifs.good())
{
ul = ifs.get();
if (ifs.good()) vbs8in.push_back(bitset<8>(ul));
}

// Print out bitset array again as char 0,1
for (ivbs8 = vbs8in.begin(); ivbs8!=vbs8in.end(); ivbs8++) cout << *ivbs8 << endl;

return 0;
}

As you can see, you can access the bits (j) in the bytes in an array (i) simply with array[j], which makes bit-handling pretty simple. I just can't help it, I like MS...