Sunday, March 9, 2014

What is the difference between kill-6 and kill -9?

IGKILL and SIGABRT are two type of signals that are sent to process to terminate it.

SIGKILL is equivalent of "kill -9" and is used to kill zombie processes, processes that are already dead and waiting for their parent processes to reap them.
SIGABRT is equivalent of "kill -6" and is used to terminate/abort running processes.

SIGKILL signal cannot be caught or ignored and the receiving process cannot perform any clean-up upon receiving this signal.
SIGABRT signal can be caught, but it cannot be blocked.


  1. can we kill zombie process? I dont think so..

  2. A zombie process is just a place holder in the process table. It remains there until its parent issues a wait system call.

  3. Manikandan SomasundaramJanuary 15, 2019 at 7:19 AM

    you can't kill zombie process