In this tutorial, I will explain a shell script that check if service is running and if it is not then will try to start it.
Its good for system admin to make sure the crucial services are running all the time.
Shell Script to check service status
This script will check the status of any init.d service and start that service if it is not running.
#!/bin/bash
if [ "$#" = 0 ]
then
echo "Usage $0 "exit 1
fi
service=$1
is_running=`ps aux | grep -v grep| grep -v "$0" | grep $service| wc -l | awk '{print $1}'`
if [ $is_running != "0" ] ;
then
echo "Service $service is running"
else
echo
initd=`ls /etc/init.d/ | grep $service | wc -l | awk '{ print $1 }'`
if [ $initd = "1" ];
then
startup=`ls /etc/init.d/ | grep $service`echo -n "Found startap script /etc/init.d/${startup}. Start it? Y/n ? "
read answer
if [ $answer = "y" -o $answer = "Y" ];
then
echo "Starting service..."/etc/init.d/${startup} start
fi
fi
fi
Results
bobbin@linoxide:/$ ./service.sh apparmor
Service apparmor is not running
Found startap script /etc/init.d/apparmor. Start it? Y/n ? Y
Starting service...
* Starting AppArmor profiles [OK]
Learn this Script Line By Line
#check if service name passed to script as argument, if there no arguments (0) do next
if [ "$#" = 0 ]
then
"Usage $0 " #write to terminal usage
echo
#since no arguments – we need to exit script and user re-run it
exit 1
fi
#get service name from first argument
service=$1
#this check ,if service running using ps command, after we remove our process from output, since script will also match, with wc we count number of matching lines.
is_running=`ps aux | grep -v grep| grep -v "$0" | grep $service| wc -l | awk '{print $1}'`
#is number of lines are not 0 do next
if [ $is_running != "0" ] ;
then
#just put this line to terminal
echo "Service $service is running"
#if number of precesses is 0
else
#Service $service is not running" #just put this string to terminal
echo
#checking for files in /etc/init.d
(directory with start-up scripts) with name similar to service
initd=`ls /etc/init.d/ | grep $service | wc -l | awk '{ print $1 }'`
#if there is script with similar name
if [ $initd = "1" ];
then
#this line get name of startup script (ls - lists files in directory
startup=`ls /etc/init.d/ | grep $service`
echo -n "Found startap script /etc/init.d/${startup}. Start it? Y/n ? "
#waiting for user answer
read answer
#if answer Y or y
if [ $answer = "y" -o $answer = "Y" ];
then
echo "Starting service..."
#running startup script
/etc/init.d/${startup} start
fi
#exit of if loop
fi
#exit of if loop
fi
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