使用系统调用pipe()建立一条管道，系统调用fork()分别创建两个子进程，它们分别向管道写一句话，如：

Child process1 is sending a message!

Child process2 is sending a message!

父进程分别从管道读出来自两个子进程的信息，显示在屏幕上。两个子进程并发执行。

实现管道的互斥使用。当一个子进程正在对管道进行写操作时，另一个欲写入管道的子进程必须等待。 使用系统调用lockf(fd[1],1,0)实现对管道的加锁操作，用lockf(fd[1],0,0)解除对管道的锁定。

实现父子进程的同步，当父进程试图从一空管道中读取数据时，便进入等待状态，直到子进程将数据写入管道返回后，才将其唤醒。

-Using the system call pipe () to build a pipeline system call fork () to create two sub-processes, respectively, which were written to the channel word, such as:

　　 Child process1 is sending a message!

　　 Child process2 is sending a message!

Parent were read from the pipe from the two sub-processes of information displayed on the screen. Concurrent execution of two sub-processes.

The exclusive use of Tube. When a child process is to write to the pipeline, another pipeline like to write to the child process to wait. Using the system call lockf (fd [1], 1,0) to achieve lock on the pipeline operation, with lockf (fd [1], 0,0) lifting of the lock channel.

Son process to achieve the synchronization, when the parent tried to read an empty pipe, they enter the wait state until the child process to write data pipeline to return only after its wake.