get the size of folder contents

du -sh 

Output

15M big_folder
0 dead.letter
4.0K some_file
4.0K some_other_file

challenges with grails unique: true

Grails does not evaluate a unique constraint at GORM level but at the database level

    static constraints = {
        property unique: true
    }

This means that you would not get a grails.validation.ValidationException but a org.springframework.dao.DataIntegrityViolationException.

This means that

domainInstance.validate()

would not capture a duplicate "property"

Sometimes cron runs twice

I suspected cron was running twice. I confirmed by checking the system logs

grep CRON /var/log/syslog

Then I killed cron and restarted it

sudo /etc/init.d/cron stop
sudo /etc/init.d/cron start

Tail vs Less

Learnt a good chunk about less and tail from this site http://www.brianstorti.com/stop-using-tail/ 

Access child components in vue.js