I'm fighting a bug in IntelliJ where nailgun instances screw up when SNAPSHOT dependencies are updated. I want to automate killing all processes that contain nailgun in their name.

So far I can get all relevant PIDs like so:

ps -x -o pid,cmd | grep nailgun | cut -f 1 -d ' '

This gives me for example:


I can go and run kill for each of them manually, like kill 26759 etc. But piping doesn't work:

ps -x -o pid,cmd | grep nailgun | cut -f 1 -d ' ' | kill

This just prints

kill: usage: kill [-s sigspec | -n signum | -sigspec] pid | jobspec ... or kill -l [sigspec]

How do I pipe the list of PIDs to kill?

1 Answer 1


Putting the PIDs onto one line with xargs works:

ps -x -o pid,cmd | grep nailgun | cut -f 1 -d ' ' | xargs kill

The only annoyance is that this prints kill: (xyz): No such process for the grep instance which shows up in the ps list as well.

Another alternative:

pgrep -f nailgun | xargs kill
  • 6
    If you’re going to use pgrep, you might as well use pkill. Commented Jun 11, 2017 at 15:22
  • It works better because kill doesn't read stdin; it wants the pids as args, which xargs does.
    – Jeff Schaller
    Commented Jun 11, 2017 at 15:58
  • See also whereis, pipeline and ls. Commented Jun 11, 2017 at 17:52
  • You could also just add another grep to filter our 'grep' in the results e..g ps -x -o pid,cmd | grep nailgun | grep -v 'grep' | cut -f 1 -d ' ' | xargs kill. FYI for me I had to cut -f 2 -d ' ' as well. Commented Jan 4, 2019 at 11:13

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