BASH. Make the result of one command to be an argument of another

Question

How can I make the result of one command to be an argument of another? I'm trying to kill child process by pid of parent process and use for it pgrep

Example: pgrep -P <PID>

But after I need to kill the PID which I get from pgrep

pgrep -P <PID> | kill - it doesn't work(

Thank you!

score 1 · Answer 1 · answered Nov 02 '17 at 09:23

1

With single pkill command:

pkill -P <PID> --signal SIGTERM

--signal signal
Defines the signal to send to each matched process. Either the numeric or the symbolic signal name can be used. (pkill only.)

answered Nov 02 '17 at 09:23

RomanPerekhrest

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score 0 · Accepted Answer · answered Nov 02 '17 at 09:12

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Try this:

VALUE="$(pgrep -P <PID>)"
kill ${VALUE}

answered Nov 02 '17 at 09:12

Bouramas

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Yes but I don't want to create env var – Avrel Dusop Nov 02 '17 at 09:18
See this post [here](https://stackoverflow.com/questions/3510673/find-and-kill-a-process-in-one-line-using-bash-and-regex) or do what @Kavli suggested below. – Bouramas Nov 02 '17 at 09:21
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@Avrel It's not an environment variable unless you `export` it, but you can easily combine these two lines anyway. – Tom Fenech Nov 02 '17 at 09:29

score 0 · Answer 3 · answered Nov 02 '17 at 09:16

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You use backticks for that. Like this:

kill `pgrep -P <PID>`

answered Nov 02 '17 at 09:16

Kavli

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`$( )` is the preferred syntax. – Tom Fenech Nov 02 '17 at 09:27

score 0 · Answer 4 · answered Nov 02 '17 at 09:22

0

this should work for you

kill -9 `command`

and as far as getting the pid is concerned see examples below

kill -9 `pgrep executable`
kill -9 `pgrep ps`
kill -9 `pgrep bash`

or your command

kill -9 `pgrep -P <PID>`

answered Nov 02 '17 at 09:22

asio_guy

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You should **never start with `kill -9`**, since it won't allow the process to gracefully die (close file descriptors, free resources, etc). Instead, use `kill -INT`, or `kill -TERM` (the same as `kill`). Only as the last resort, use `kill -9`. – randomir Nov 02 '17 at 12:52

score -1 · Answer 5 · answered Nov 02 '17 at 09:26

-1

You probably want "kill -9" as well:

pgrep -P <PID> | xargs -n1 kill -9

To test what it is going to do in advance try:

pgrep -P <PID> | xargs -n1 echo kill -9

answered Nov 02 '17 at 09:26

Delyan Tashev

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Why would you _probably_ want `kill -9`? – Tom Fenech Nov 02 '17 at 09:26
xargs - that what I wanted – Avrel Dusop Dec 11 '17 at 16:05

BASH. Make the result of one command to be an argument of another

5 Answers5