写linux下的用户程序，其中一个为父进程，它创建了另外2个子进程，这2个子进程通过某种IPC机制实现进程间通信。要求分别在PC机上和在ARM开发板上测试实现。-Write the user program under linux, one of the parent process, it creates two separate sub-process, the two sub-process through some IPC mechanism to achieve inter-proce