* | any value |
, | value list separator |
- | range of values |
/ | step values |
Cronjob is a fantastic feature, that enables you to schedule your repetitive jobs. 0 */4 * * * let's you run a script/program every 4 hours. All you need to do is, configure this cronjob in your system with the script/program you want to run, which can be done in an unix/linux based operating system as following: Step 1: Edit your cronjob file by running "crontab -e" command Step 2: Add the following line for every 4 hours interval: 0 */4 * * * /path/to/your/script-or-program Step 3: Save the file. That's it!
Cronjob let's you run a script to do a repetitive job in an efficent way, here's how you can schedule a cronjob for every 4 hours: Step 1: Edit your cronjob file by running "crontab -e" command Step 2) Add the following line for every 4 hours interval: 0 */4 * * * /path/to/your/script Step 3: Save the file. That's it!
Absolutely, this is the correct expression for the magic you are looking for. 0 */4 * * * let's you run a cronjob every 4 hours.
There are potentially infinte examples for it. Think about any job that you want to run every 4 hours, it can be processing some data, generating a report, crawling an external source, pinging another service etc. For example, if I want to check uptime of my website in every 1 minute, I can write a program to do this for me using this powerful functionality of scheduling.