管道创建和关闭，管道通信主要用于不同进程之间的通信！-Pipeline creation and closure of the main communication channels for communication between different processes!

进程的管道通信，父进程调用fork（）生成两个子进程，完成父子进程之间的通信。-Process pipeline communication, the parent process calls fork () to generate two sub-processes, to complete the communication between the parent and child processes.

编写一段程序，使其用管道来实现父子进程之间的进程通信-Write a program to use the pipeline to implement the process of communication between parent and child