macos - How do I close an open port from the terminal on the Mac?

Question

I opened port #5955 from a java class to comunicate from a client. How do i close this port after I am done? and also which command can show me if port open or closed?

Answer 1

1. Find out the process ID (PID) which is occupying the port number (e.g., 5955) you would like to free

   sudo lsof -i :5955
   

2. Kill the process which is currently using the port using its PID

   sudo kill -9 PID