I want to parse binary string into message c++

[정등혁]

#include <iostream>

#include <fstream>

#include <string>

#include "EncodeMessage.pb.h"

using namespace std;

string HexString2BinaryString(string sHex)

{

string sReturn = "";

int sLen = sHex.length();

for (int i = 0; i < sLen; ++i)

{

switch (sHex[i])

{

case '0': sReturn.append("0000"); break;

case '1': sReturn.append("0001"); break;

case '2': sReturn.append("0010"); break;

case '3': sReturn.append("0011"); break;

case '4': sReturn.append("0100"); break;

case '5': sReturn.append("0101"); break;

case '6': sReturn.append("0110"); break;

case '7': sReturn.append("0111"); break;

case '8': sReturn.append("1000"); break;

case '9': sReturn.append("1001"); break;

case 'a': sReturn.append("1010"); break;

case 'b': sReturn.append("1011"); break;

case 'c': sReturn.append("1100"); break;

case 'd': sReturn.append("1101"); break;

case 'e': sReturn.append("1110"); break;

case 'f': sReturn.append("1111"); break;

}

}

int rLen = sReturn.length();

int i;

for (i = 0; i < rLen; i++)

{

if (sReturn[i] != '0')

{

break;

}

}

sReturn.replace(0, i, "");

return sReturn;

}

// Main function:  Reads the entire address book from a file and prints all

//   the information inside.

int main(int argc, char* argv[]) {

// Verify that the version of the library that we linked against is

// compatible with the version of the headers we compiled against.

GOOGLE_PROTOBUF_VERIFY_VERSION;

// Inset hex type string -> change to binary string

string hexStr;

cin >> hexStr;

string binaryStr = HexString2BinaryString(hexStr);

//cout << binaryStr << endl;

machineInfo::msgOption option;

{

// ** I want to use 'binaryStr' variable to parse 'option' variable

// can you help me out?

//fstream input("output.bin", ios::in | ios::binary);

//if (!option.ParseFromIstream(&input)) {

// cerr << "Failed to parse address book." << endl;

// return -1;

//}

}

// Optional:  Delete all global objects allocated by libprotobuf.

google::protobuf::ShutdownProtobufLibrary();

return 0;

}

I want to parse binary string into message 'option'

Can I make message without using "output.bin" file, by using 'binary string' I made in cpp. 

[Josh Haberman]

If you have a proper binary buffer, you should be able to pass it to option.ParseFromString(binaryString).

But your HexString2BinaryString() function is not correct. You need to convert each pair of hex digits into a single binary byte. Right now you are converting the hex digits into a human-readable text string of binary digits, which is not what you want.