A c++ factorial script I wrote in like 5 minutes

Factoral

#include <iostream>
#include <string>

unsigned long factoral(const unsigned long i) {

    if(i == 1)
        return 1;

    return i * factoral(i - 1);
    
}

int main()
{
    while(true) {
        std::cout << "Enter a number to find the factoral, or press q to quit: ";
        std::string string;
        getline(std::cin, string);
        
        bool onlyDigits = true;
        
        for(char ch : string) {
            
            if(ch == 'q' || ch == 'Q')
                return 0;
            
            if(onlyDigits == true && !isdigit(ch))
                    onlyDigits = false;
        }
        
        if(onlyDigits){
            std::cout << factoral(stoi(string)) << "\n";
        }
    }
}