Scripting

DON'T Forget To Define The Script and Log Output Paths Before Running the Below Commands.

zenigma.sh, is a shell script which append "Hello Zenigma!" for every 15 seconds into a temp file named as “zenigma.log”.

If you need too run the shell script as a daemon process,

#make script executable
chmod +x zenigma.sh 
nohup ./zenigma.sh > zenigma.out 2>&1 &

Or, you can add zenigma.sh to /etc/systemd/system to run it as a service,

#make script executable
chmod +x zenigma.sh 
#copy service file to, Linux system directory.
cp /path/zenigma.service /etc/systemd/system 
#if you want it to start on the boot.
systemctl enable zenigma.service 
systemctl start zenigma.service 

record_counter.sh, will count records and when it reaches to 20, will delete the previous records,

#make script executable also need to x zenigma.sh since it included inside of counter.sh
chmod +x record_counter.sh 
nohup ./record_counter.sh > record_counter.out 2>&1 &

Instead of constantly running this script as a daemon or service, we will be using crontab to schedule it with 5 mins of periods, and log the activities such as time, line count, and file deletion status.

#make script executable also need to x zenigma.sh since it included inside of counter.sh
chmod +x counter_with_logging.sh
#run the below command to schecule a cronjob, or manually add it to cron file with crontab -e
echo "*/5 * * * * /counter_with_logging.sh" | crontab -