#include <iostream>
#include <unistd.h>

int main() {
    long pages = sysconf(_SC_AVPHYS_PAGES);
    long page_size = sysconf(_SC_PAGE_SIZE);
    long free_memory = pages * page_size;

    std::cout << "pages: " << pages << ";  page_size: " << page_size << ";  free: " << free_memory;
}