file with a string that is hex. need to format it so i can use it in program

Question

hello, i have a hex valued string that is saved in a text file. I want to get it into a c style include format to just copy and paste into my code. i tried using xxd that has a feature to do that but for some reason when i use my file it takes that string (it considers it non hex) and further converts it into hexadecimal.

anyway around this or an easier way to do this in c++. I am not sure. pretty new to c++ and just learning here.

sample of the contents of the file are as follows:

AFAB2591CFB70E77C7C417D8C389507A541D0350752EE9E8C12D76E8674677C166A5ACA65ECFDE7EC90DC8E7D6D621438FEF7DD38B0EDEA3D44BDB9D6E7E1CA0FBA30B507EA70B2A52434F64092EC13BD12F8F1C2BED6EE1ADE7

so getting it like 0xAF, 0xAB etc is what i am looking for.

i also noticed that when i use xxd even if i just put A in the file...its result is 410a. I don't understand that either. is it showing a word rather than just a byte?

Answer 1

ok well first dude get the code to find the string like so

#include <iostream>
#include <conio.h>
#include <fstream>
#include <iostream>

using namespace std;

class FindHex {
    string x, y;
  public:
    void set_values (string,string);
   string found () {return (x,y);}
};

void FindHex::set_values ( string a, string b) {
    cout<<a<<" "<<b;
    x = a;
    y = b;
}

FindHex hex;

int main () {
    char Name[10];
    char LName[10];
    ifstream inf("Data.txt");

    while(!inf.getline(Name, 30, '0x').eof())
    {
        inf.getline(LName, sizeof(LName));
        hex.set_values (Name,LName);
        hex.found();
        cin.ignore();    
    }

}

Answer 2

string s = ...; // Read the string into this
stringstream buffer;

for (size_t i = 0; i < s.length(); i += 2) {
   char tmp[3] = { s[i], s[i + 1], 0 };
   buffer << (char)strtol(tmp, NULL, 16);
}

const string final = buffer.str();

There you go!

Answer 3

You can use any regular expression editor to convert

AFAB2591CFB70...

to 0xAF, 0xAB, 0x25, 0x91, 0xCF, 0xB7, ...

I use MSFT Visual Studio and this is a snap with the RE option of it's "Find-and-Replace" tool. Find any expression consisting of any char in the set [0-9A-Fa-f] followed by another char in the same set; tag the expression; replace it with "0x" + tagged expression + ", ". (Don't match whole words.)

If you're using a different GUI dev tool, you should be easily able to find a command line sed (Linux or Cygwin) or something similar.

Answer 4

Looks like homework, but what the heck. Compile this into filter.exe and then:

filter < inputfile.txt > outputfile.cpp

#include <iostream>
using namespace std;

int main(int argc, char* argv[])
{
    char a, b;
    while (!cin.eof()) {
        cin >> a >> b;
        cout << "0x" << a << b << ", ";
    }
    return 0;
}