fun - fun
c语言的函数声明和typedef
在《UNIX环境高级编程》、《UNIX® Network Programming Volume 1, Third Edition: The Sockets Networking API》都讨论信号处理，并且都解释了下面这个函数原型：
unix环境高级编程中的信号术语和语义
1. 信号产生：a signal is generated for a process (or sent to a process) when the event that causes the signal occurs. The event could be a hardware exception (e.g., divide by 0), a software condition (e.g., an alarm timer expiring), a terminal-generated signal, or a call to the kill function. When the signal is generated, the kernel usually sets a flag of some form in the process table.
linux设备驱动在2.6.32上的编译-scullp