linux下用C语言写的聊天程序！/*BUG and NOTE: Not join protect to Shared Memory Segments,example Semaphore Arrays. Not check the parameters validity. When transmit may be error. If the client program no right exit,others cannot know,the service program sh

信号量的使用主要是用来保护共享资源，使得资源在一个时刻只有一个进程（线程）所拥有。-Semaphore is mainly used to protect the use of shared resources, making the resource at a time only one process (thread) owned.

编写一个生产者－消费者程序组，支持多个生产者和消费者，生产者进程数为2， 消费者进程数为3。 生产者与消费者之间使用共享内存进行数据传递，并使用信号量对数据的内容进行保护。-Preparation of a producer- consumer program group, supports multiple producers and consumers, the the producer process for 2 Consumers number of processes.