I want to kill all processes that result from the following command

Question

The following command will display all the PID's running for vmstat1:

ps -ef | grep "vmstat 1" | awk '{ print $2 }'

My question is, how do I kill them all, if there's like 20 of them at once?

Answer 1

If your command produces list of PIDs, then simply pipe it into:

xargs kill

Note that your command will match the grep command as well, so consider adding something like |grep -v grep before the original grep command.

Answer 2

Just use pkill. Though not a standard command, it is found in many Unices and is dedicated to this kind of tasks.

pkill -f 'vmstat 1'

Also note that your grep will match vmstat 1 but also vmstat 10 and grep vmstat 1 (so would that pkill above), and awk is a superset of grep. To be more robust, you could do instead:

ps -eo pid,args | awk '$2 == "vmstat" && $3 == "1" {print $1}' | xargs kill

Or

pkill -xf 'vmstat 1'

Answer 3

If you are already using awk, you can do

ps -ef | grep "vmstat 1" | awk '!/grep/{ print "kill " $2 }' | bash

It will output a list of kill commands, and as every one of the commands kills a single process, you will not run into potential argument list too long (though it's highly unlikely when going over running processes), and I added a pattern to avoid matching the grep process itself, as killing it may cut your list short.