Time/space complexity of string splitting/object creation in c++

I'am struggling to figure out the time complexity of a piece of code that I have that takes a user input from 1 line e.g open 1 0, and splits the input via spaces, then allows the user to create a new 'account' object on the heap. I am thinking it is an O(n^2) operation as it contains 2 while loops, plus an additional function call, this could be completely wrong.

int main(){

    std::vector <std::string> parameters;
    std::string userCommand;

    // Make a new account manager object for a new user
    AccountManager accounts = AccountManager();

    while (userCommand != "exit"){

        parameters.clear(); // Clear ready for next command
        std::cout << std::endl << ">>> ";

        std::getline(std::cin, userCommand);
        char* cstr = new char[userCommand.length() + 1];
        strcpy(cstr, userCommand.c_str());

        char* token;
        token = strtok(cstr, " ");

        while (token != nullptr){
            parameters.push_back(token);
            token = strtok(nullptr, " ");
        }

        // This calls a function that creates a creates a new object on the heap
        accounts.openAccount(parameters[1], parameters[2]);
    }
}

The complexity is linear in the total user input length on both space and time.

All the individual operations iterate over user input only a constant amount of times, including the inner loop. Therefore with n the total length of user input time the time complexity is Theta(n).

Similarly memory is only used to store a constant multiple of the user input length, implying Theta(n) space complexity.

This is assuming that the AccountManager operations which you didn't elaborate on are not dominating.