kill-9-1

If 25% of hacker news folks attend, then the talk will have about 100,000 people. Jeremy - you better get a whole football field for your talk!

backgrounding a job to sleep/kill a pid isn't necessarily a great idea imho. here, if the port in question is open then then you will pass the wait relatively quickly, but you still have a timer set to kill the pid. A short timer probably won't cause an issue, but the longer you wait the more likely it becomes that the kernel will assign that pid to a new process that you probably don't want killed. especially if you are launching two new pids for each possible port.