□ ps | awk '{print $1}' | xargs kill -9
○ ps : It prints the running processes
○ | awk '{print $1}' : It prints the first column of the result of ps(=pid)
○ | xargs kill -9: It compulsorily kills the processes of the result of the output(=pid)
It is also posted at : http://cysecguide.blogspot.com/2016/09/method-of-killing-all-processes-of.html