simple hexdump

main.cpp

#include <iostream>
#include <fstream>
#include <iomanip>
#include <vector>

using std::cerr;
using std::cout;
using std::endl;
using std::hex;
using std::ifstream;
using std::ios;
using std::setfill;
using std::setw;
using std::vector;

/**
 * @brief Print the hex dump of a file.
 *
 * Read the specified file in binary mode and prints its contents in a hex dump format.
 * Show the linear address (in hex) on the left and up to 20 bytes of data on the right.
 *
 * @param filename The name of the file to dump.
 * @return int Returns 0 on success, non-zero on failure.
 */
int hexDump(const char* filename) {
    ifstream file(filename, ios::binary);
    if (!file) {
        cerr << "Error: Could not open file " << filename << endl;
        return 1;
    }

    const int bytesPerLine = 20;
    unsigned long address = 0;
    vector<unsigned char> buffer(bytesPerLine);

    while (file) {
        file.read(reinterpret_cast<char*>(buffer.data()), bytesPerLine);
        std::streamsize bytesRead = file.gcount();
        if (bytesRead <= 0) break;

        // Print linear address.
        cout << setfill('0') << setw(8) << hex << address << ": ";

        // Print each byte in hex with a space.
        for (std::streamsize i = 0; i < bytesRead; i++) {
            cout << setfill('0') << setw(2) << hex << static_cast<int>(buffer[i]);
            if (i != bytesRead - 1)
                cout << " ";
        }
        cout << endl;
        address += bytesRead;
    }
    return 0;
}

/**
 * @brief Main function.
 *
 * Parse command-line arguments, call the hexDump function.
 *
 * @param argc Number of command-line arguments.
 * @param argv Array of command-line argument strings.
 * @return int Returns 0 on success, non-zero on failure.
 */
int main(int argc, char* argv[]) {
    if (argc < 2) {
        cerr << "Usage: " << argv[0] << " <filename> is required" << endl;
        return 1;
    }
    return hexDump(argv[1]);
}