fork 父子进程

#include
#include

int main()
{
  int pid;

    pid = fork();
   if (pid == 0)  // child process
   {
        printf("child process PID=%d, parent process PID=%d\n", getpid(), getppid());
    }
    else if (pid > 0)  // parent process
    {
        printf("parent process PID=%d, pparent process PID=%d\n", getpid(), getppid());
    }
    return 0;
}

results:   child process PID=2215, parent process PID=1
              parent process PID=2214, pparent process PID=2011