script bash to check that a service is running

Question

I have a customised linux version, kernel version is 4.1.15-klk my platform architecture is armv7l GNU/Linux

I am trying to check if my process is running or not :

I tried this:

#!/bin/sh
service=myservice

if [ $(ps | grep -v grep | grep $service | wc -l) -gt 0 ]
then
 echo "$service is running!!!"
else
 echo "$service is not running!!!"
fi

but it is giving me "myservice is running!!!" whether it is running or not

I can't use pgrep since it is not available in my system

any ideas? thanks!

When the service is __not__ running, what is the output of `ps | grep -v grep | grep $service` ? — John1024, Dec 22 '17 at 20:49
when the service is not running I got nothing for the output of `ps | grep -v grep | grep $service` and when it is running it display the service information in one line — sabrina2020, Dec 22 '17 at 20:59
Unless something else comes up, I still suspect that that is where your problem is. In your script, try `if [ $(ps | grep -v grep | grep "$service" | tee ~/service.log | wc -l) -gt 0 ]` and then inspect `~/service.log` to verify that what the output really is. — John1024, Dec 22 '17 at 21:12

Feriman · Answer 1 · 2023-04-11T08:42:05.603

9

Based on this question, the short and scriptable way is:

systemctl is-active --quiet service

It will exit with code zero, if the service is running.

Example for printing whether the sshd service is running or not:

systemctl is-active --quiet sshd && echo "sshd is running" || echo "sshd is NOT running"

edited Apr 11 '23 at 08:42

answered Sep 09 '19 at 19:47

Feriman

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This is much, much better than any other answer here. On any distro which uses systemd, this is THE right answer. – Wildcard Sep 11 '19 at 09:18
1

Thanks for the answer! How can I use it with an `if`? I have done something like `STATUS=$(systemctl is-active service)` and then `if [ "$STATUS" = "active" ]` or `if [ "$STATUS" = "inactive" ]` ? – Ferran Maylinch Nov 02 '21 at 08:27
Answering to my question. I found it here: https://unix.stackexchange.com/questions/22726/how-to-conditionally-do-something-if-a-command-succeeded-or-failed. For example: `if systemctl is-active --quiet service; then ...` or `if ! systemctl is-active --quiet service; then ...`. – Ferran Maylinch Nov 02 '21 at 08:47
1

@FerranMaylinch you can also access the previous commands exit code via `$?` – sudo soul Apr 11 '22 at 04:47
This does not appear to work for `type=exec`. I just tried this on podman and the problem is the service deactivates after running. – Grant Curell Feb 08 '23 at 17:00

score 2 · Answer 2 · edited Jun 07 '19 at 19:13

2

Use below script to check whether service running or not. I tested for the mysql service, making it up and down and in both the conditions it's working fine.

#!/bin/bash
i=`ps -eaf | grep -i mysql |sed '/^$/d' | wc -l`
echo $i
if [[ $i > 1 ]]
then
  echo "service is running"
else
  echo "service not running"
fi

edited Jun 07 '19 at 19:13

Jeff Schaller

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answered Dec 24 '17 at 08:27

Praveen Kumar BS

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score 1 · Answer 3 · answered Dec 22 '17 at 21:40

1

finally using this post, I was able to solve my problem:

#!/bin/sh
service=myservice

case  "$(pidof $service | wc -w)" in
0) echo "$service is not running!!!"
;;
1) echo "$service is  running!!!"
;;
*) echo "multiple instances running"
;;
esac

answered Dec 22 '17 at 21:40

sabrina2020

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It's not working well in any case, for example it's not working properly for fail2ban. – Feriman Dec 28 '22 at 13:53

score 0 · Answer 4 · answered Dec 22 '17 at 20:51

0

On Ubuntu and CentOs systems, I'd use ps aux instead of ps alone.

answered Dec 22 '17 at 20:51

John

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`ps aux` is not supported in my system: `ps aux ps: invalid option -- 'a' BusyBox v1.24.1 (2017-07-21 14:28:39 CEST) multi-call binary. Usage: ps ` – sabrina2020 Dec 22 '17 at 21:00
if you run `ps` is the service listed in your output? – John Dec 22 '17 at 21:04
1

yes the service is listed using only `ps` – sabrina2020 Dec 22 '17 at 21:05
Try just `ps | grep $service` – John Dec 22 '17 at 21:28

score 0 · Answer 5 · edited Jun 07 '19 at 19:27

You can use the case function to better control it.

#!/bin/bash
i=$(ps -eaf | grep -i mysql | sed '/^$/d' | wc -l); echo $i
case $i in
    0) echo "The mysql service is 'not running'.";;
    1) echo "The mysql Service has 'failed'. You may need to restart the service";;
    2) echo "The mysql service is 'running'. No problems detected.";;
esac

The first example has an error in it. A space must be before & After '|', '||', '&' or '&&'

So it should read

i=$(ps -eaf | grep -i mysql | sed '/^$/d' | wc -l); echo $i

script bash to check that a service is running

5 Answers5