CRON command to run URL address every 30 minutes in Linux

1. Create or edit cron job enter following command:

cat /etc/crontab
crontab -e

Above command will open a crontab file, if exists, otherwise an empty file for creating a new crontab.

2. You can use the following CRON command to run a URL address every 30 minutes in Linux:

*/30 * * * * curl -s http://www.example.com/example

This CRON expression runs the curl command, which is used to retrieve the content of a URL, every 30 minutes (*/30). The * symbols indicate that the command should be run every hour, every day of the month, every month, and every day of the week.