c++ get environment variable

#include <iostream>
#include <cstdlib>

int main() {
    char* env_var = std::getenv("MY_ENV_VARIABLE");
    if (env_var != nullptr) {
        std::cout << "The value of MY_ENV_VARIABLE is: " << env_var << std::endl;
    } else {
        std::cout << "MY_ENV_VARIABLE is not set." << std::endl;
    }
    return 0;
}