在Linux中，不使用GDB的实时调试，如何在C程序挂起时找到它的状态?

We have an ancient network application (a client program running on one machine and a server program on another). It usually works fine, but in rare cases it hangs. We are yet to identify what exactly is causing the hang. It's plain old socket programming written in C.We have an ancient network application (a clien