[cs631apue] Address in use

[wwang22]

Hi, professor and all,

It happens a lot that once I run my program and occupy a port, and next 
time I rerun it , the "Address in use" error always shows up.
It seems that even though the program is end, the occupied port is not 
released. So, I have to set a different port each time to test my 
program.
Is that normal? I don't know what's wrong. How should I fix the 
problem?

Thank you very much.

Wen