lsof -wni tcp:3000
kill -9 PID

By meanstackbasit
kill -9 $(lsof -i tcp:3000 -t)

# To kill a process in a Ruby on Rails application, you can make use of the `Process` class and the `kill` method.
# First, find the Process ID (PID) of the process you want to terminate. This can be done using the command line or by checking the process list of your operating system.
# Once you have the PID, you can use the `kill` method to terminate the process. Here's an example:
pid = 12345 # Replace 12345 with the actual PID of the process you want to kill
begin Process.kill('TERM', pid) # Terminate the process with the specified PID using the 'TERM' signal puts "Process with PID #{pid} has been terminated."
rescue Errno::ESRCH puts "Process with PID #{pid} not found."
end