Pattern scan with mask [C++]

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

// Function to perform a pattern scan with a mask
std::vector<long> patternScanWithMask(const char* filename, const char* pattern, const char* mask) {
    std::vector<long> occurrences;
    std::ifstream file(filename, std::ios::binary);

    if (!file.is_open()) {
        std::cout << "Error opening file: " << filename << std::endl;
        return occurrences;
    }

    file.seekg(0, std::ios::end);
    std::streampos fileSize = file.tellg();
    file.seekg(0, std::ios::beg);

    // Read the entire file into a buffer
    std::vector<char> buffer(fileSize);
    file.read(buffer.data(), fileSize);

    file.close();

    int patternLength = strlen(pattern);
    int maskLength = strlen(mask);
    int bufferLength = fileSize;

    for (int i = 0; i <= bufferLength - patternLength; ++i) {
        bool found = true;
        for (int j = 0; j < patternLength; ++j) {
            if (mask[j] == 'x' && buffer[i + j] != pattern[j]) {
                found = false;
                break;
            }
        }

        if (found) {
            occurrences.push_back(i);
        }
    }

    return occurrences;
}

int main() {
    const char* filename = "example.exe";
    const char* pattern = "\x48\x8B\x05\x00\x00\x00\x00"; // Example pattern to search for
    const char* mask = "xxx????"; // Mask: 'x' means compare, '?' means ignore

    std::vector<long> occurrences = patternScanWithMask(filename, pattern, mask);

    if (occurrences.empty()) {
        std::cout << "Pattern not found in the file." << std::endl;
    } else {
        std::cout << "Pattern found at offsets: ";
        for (const auto& offset : occurrences) {
            std::cout << offset << " ";
        }
        std::cout << std::endl;
    }

    return 0;
}