SSH Script sensor - monitor process/service uptime

I would like to use SSH script sensor to monitor process uptime. I have created a script under /var/prtg/scripts:

#!/bin/sh

ps -C java -o etimes= 2>&1 1>/dev/null

if [ $? -ne 0 ]; then
  echo "1:$?:$1 down"
else
  echo "0:$?:OK"
fi

and i get 0:1:OK as the result which is fine because the service/process is running but the command: ps -C java -o etimes= gives service/process uptime in seconds and i would like that number in my result. Something like "0:25444:uptime in seconds". I guess that is doable but i'm doing something wrong.

Ty.

linux prtg ssh ssh-script ubuntu uptimr