linux系统下的多进程编程加共享内存操作代码，主要应用多进程，和共享内存操作，一个主进程和两个子进程，两个子进程之间数据的传递，控制，一个子进程负责与串口的通信，一个负责记录和保存-Multi process programming under Linux system with shared memory operation code, the main application of multiple processes, and the shared memory operation, a