outputing to a binary file

I am trying to output a string to a binary file, but I have no idea how to do it at all
say if I have a string:
string A = "1010";
I want to output it as a byte to the binary file
and I need to format it as 00001010

I guess I need to extract it bit by bit from the string and somehow using bit operator to assign the bit to the byte, then output the byte to the binary file
But I can't find any reference on the web about that

Does anyone know how and give me an example of it?
Also, do I need to output it byte by byte to the binary file?

If I want to read a binary file and convert it back to a string or a character, how can I do it?
nofearseAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

jkrCommented:
The easiest way would be to

#include <stdlib.h>
#include <string>
using namespace std;


//...


typedef unsigned char BYTE;

string A = "1010";
char* pcCnvEnd = NULL;

BYTE b = ( BYTE) strtol ( A.c_str (), &pcCnvEnd, 2);

if ( *pcCnvEnd) {

  // some error occured
}
0
jkrCommented:
BTW, just a partial solution, as I assume this is homework somehow :o)
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
nofearseAuthor Commented:
where is the filestream?
how does bit operator <<  work?
confused :S
0
dude_1967Commented:
nofear,

Here is an efficient way to get you started:

In my opionion, it would be wise to use STL-bitmaps to effectively complete the development goal (even if it is an assignment). Please look carefully at the following. All that is now needed is to put the byte into an output file stream. If you use this kind of technique in homework, then please try to gain rudimentary understanding of the STL-bitmaps before using them.

Sincerely, Chris.

// Sample code

#include <bitset>
#include <string>

int main(int argc, char* argv[])
{
  // Use a STL-bitset created from a STL-string.
  ::std::string str("1010");
  ::std::bitset<8> b8(str);

  // Now we can convert the bitset to the byte.  
  unsigned char by = static_cast<unsigned char>(b8.to_ulong());
 
  // The file handling needs to be implemented...
 
  return 0;
}
0
tinchosCommented:
No comment has been added lately, so it's time to clean up this TA.
I will leave the following recommendation for this question in the Cleanup topic area:

Split: jkr {http:#9705654} & dude_1967 {http:#9714397}

Please leave any comments here within the next seven days.
PLEASE DO NOT ACCEPT THIS COMMENT AS AN ANSWER!

Tinchos
EE Cleanup Volunteer
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Software

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.