#include <cstdlib>
#include <unistd.h>

int main(int argc, const char* argv[])
{
        long pid = fork();

        //child
        if(pid == 0)
        {
                close(0);               // close std in

                char* args[] = {"ruby", "-e", "puts 'hello world'", 0};
                execvp("ruby", (char* const*)args);
                exit(0);
        }

        return 0;
}