什么是"W"的助记符,即"W"在以下宏中的含义:
int WIFEXITED (int status)
int WEXITSTATUS (int status)
int WIFSIGNALED (int status)
int WTERMSIG (int status)
int WCOREDUMP (int status)
int WIFSTOPPED (int status)
int WSTOPSIG (int status)
另请参阅流程状态完成.