了解ipc通信中的信号。在lunix中编写一段c程序，创建两个子进程执行中让父进程捕获键盘上传来的中断信号（ctrl＋c）；当捕获到该信号，父进程向两个子进程发出一种信号，而子进程捕捉到父进程发来的信号-Learn ipc communication signal. In lunix prepared for some c procedures, the creation of two sub-process of the implementation process to allow the parent to capture From the keyboard interrupt signal (ctrl　 c)　when the capture of the signal, the father of process issued to the two sub-process a signal, while the child process to capture parent process to send a signal