(PHP 4 >= 4.1.0, PHP 5)
Returns the return code of a terminated child. This function is only useful if pcntl_wifexited() returned TRUE.
参数 status 是提供给成功调用的 pcntl_waitpid() 函数的状态参数。
See also pcntl_waitpid() and pcntl_wifexited().