How do I stop the previous command in a bash script?

Question

I'm trying to build a bash script that runs unit tests on a web server.

I wish to run a simple bash script that could be (for example) in a makefile that does the following:

Assuming that the web server is written for NodeJS, here's what it could look like:

npm start &
sleep 5
npm test

The issue with this approach is that the web server will keep on running. How do I stop it after the npm test stage?

Not really an option. If I understand correctly, `killall` kills all processed that match a keyword you specify. If that's correct, trying to kill my background process would possibly kill others that I wish to leave untouched. Please correct me if that's not what `killall` does :) — goncalotomas, Dec 12 '16 at 12:32
That is exactly what `killall` does. As long as this is the only instance of npm running, one should be fine. — Jonathan Wheeler, Dec 12 '16 at 13:03

choroba · Accepted Answer · 2016-12-12T08:15:22.140

5

The PID of the last started background process is stored in $!, so pick it up after starting npm and kill it when needed:

npm start &
npm_pid=$!
...
kill $npm_pid

edited Dec 12 '16 at 08:15

answered Dec 12 '16 at 00:31

choroba

2

You want `$!` maybe? – Andreas Louv Dec 12 '16 at 00:33
@andlrc: Ouch, of course, thanks. – choroba Dec 12 '16 at 08:15
I wouldn't have found the other question if I had looked at the title, but I completely understand the duplicate flag. Either way, many thanks for the answer! :) – goncalotomas Dec 12 '16 at 12:35

score 1 · Answer 2 · answered Dec 12 '16 at 01:39

1

You might consider running the process in a screen.

screen -dmS npm npm start #Starts a detached screen named npm, and runs "npm start" inside

Later, when you need to kill the process, you can just kill the screen. When the screen dies, it will take it's child processes with it.

screen -X -S npm quit

answered Dec 12 '16 at 01:39

Guest

Completely different than what I expected. I'm going to read up on `screens`. Thanks! – goncalotomas Dec 12 '16 at 12:30

score -1 · Answer 3 · edited May 23 '17 at 11:53

-1

Perhaps a duplicate of this solution

ps -ef | grep your_process_name | grep -v grep | awk '{print $2}' | xargs kill)

edited May 23 '17 at 11:53

Community

answered Dec 12 '16 at 00:32

Jonathan Wheeler

Don't c/p another answer from StackOverflow, mark as duplicate instead. – Andreas Louv Dec 12 '16 at 00:35

3 Answers3