C++ Program, convert regular file to hexadecimal and binary - c++

Question

My HexDump that I have takes a file and outputs the ASCII hex value of that file, and also the binary values of that file. In example, when I run my program on a text file containing "Hello World!", I get
4865 6C6C 6F20 etc. So I know it is converting the direct ascii characters to the correct hex values. But, an example in my program syllabus shows that other bytes should be printed before the text.
This leads me to believe that I am not reading the entire file correctly. I think I may need to use fread() or fopen()? Please help me out. I am a C++ beginner. This is my code that I run on my txt file:
#include <iostream>
#include <iostream>
#include <fstream>
#include <string>
#include <stdio.h>
#include <stdlib.h>
#include <bitset>
using namespace std;
string stringToHexOrByte(char input, bool toByte)
{
string output;
if (toByte) {
bitset<8> temp(input);
output = temp.to_string();
}
else {
static const char hex_digits[] = "0123456789ABCDEF";
output.reserve(2);
output.push_back(hex_digits[input >> 4]);
output.push_back(hex_digits[input & 15]);
}
return output;
}
int main(int argc, char* argv[]) {
// Create a text string, which is used to output the text file
string initialInput;
// char variable in order to read char by char from file
char myChar;
//bool value to know if we have the byte parameter called
bool byteOption;
// string which will retain the converted char to hex or byte
string convChar;
string fileName;
//Check if we have -b byte Option
if (argc > 2) {
byteOption = true;
fileName = argv[2];
}
else {
byteOption = false;
fileName = argv[1];
}
// Read from the text file
fstream myFile(fileName, fstream::in);
// we will use this group variable to separate the chars printed as in the examples
int group = 1;
while (myFile >> std::noskipws >> myChar) {
// if the bynary option is selected we will print all the chars separetely
if (byteOption) {
group = 0;
}
convChar = stringToHexOrByte(myChar, byteOption);
cout << convChar;
// here we use the group to get the output expected
if (group) {
group = 0;
}
else {
cout << " ";
group = 1;
}
//clear non-printable chars
if ((int)myChar < 32) {
myChar = '.';
}
// Append to input string
initialInput.append(1, myChar);
}
// Close the file
myFile.close();
//print input
cout << " " << initialInput;
return 0;
}