what is the difference between kill -9 pid
and kill pid
command ?
Do they have different behavior ?
i know that -9 is for "SIGKILL" signal
-
If you don't specify a signal it will send SIGTERM (giving the process a chance to close itself down gracefully)– Zanna ♦Jun 27, 2016 at 6:47
1 Answer
kill pid
(which sends signal 15 (SIGTERM)) tells pid
to terminate, but said program can execute some code first or even ignore the signal. kill -9 pid
, on the other hand, forces the program to immediately terminate (it cannot be ignored).
You should always try kill pid
first, as it allows the program to do things like saving/closing open files before exiting. Only use kill -9
when you need the program to close and it won't respond to a simple kill pid
.