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How to Run Cron Job Every Minute – A Complete Guide

run cron job every minute

Cron is a time-based job scheduler in Unix-like operating systems. It is used to schedule jobs (commands or scripts) to run periodically at fixed intervals, dates, or times. Cron is a powerful tool that can automate repetitive tasks like data backups, system updates, and other administrative tasks. In this article, we will discuss how to run a cron job every minute.

Understanding Cron Syntax

Before we dive into the details of how to run a cron job every minute, let’s first understand the syntax of the cron command. Cron syntax consists of five fields:

*     *     *     *     *
-     -     -     -     -
|     |     |     |     |
|     |     |     |     +----- day of the week (0 - 6) (Sunday=0)
|     |     |     +------- month (1 - 12)
|     |     +--------- day of the month (1 - 31)
|     +----------- hour (0 - 23)
+------------- min (0 - 59)

The first five fields represent the time and date when the job will run, and the last field represents the command or script to run.

The asterisk () character is used to specify all possible values for a field. For example, the field ` ` means “run the command every minute of every hour of every day of every month of every day of the week.”

Running Cron Job Every Minute

To run a cron job every minute, we need to set the cron syntax to * * * * *. This means that the command or script will run every minute of every hour of every day of every month of every day of the week.

To set up a cron job, we need to edit the user’s crontab file by running the following command:

crontab -e

This will open the user’s crontab file in the default text editor. We can then add the following line to the file:

* * * * * command /path/to/command

Replace command with the command or script you want to run every minute, and /path/to/command with the full path to the command or script.

For example, if we want to run a script called backup.sh every minute, we can add the following line to the crontab file:

* * * * * /home/user/scripts/backup.sh

Save the crontab file and exit the text editor.

Troubleshooting Cron Job Issues

If the cron job is not running as expected, there are a few troubleshooting steps we can take to identify and fix the issue:

  • Check the system logs for any errors related to cron or the command/script being run.
  • Verify that the command/script is executable and has the correct permissions.
  • Check the crontab syntax using a tool like Crontab Guru.
  • Verify that the cron service is running using the command systemctl status cron.

Conclusion

In this article, we discussed how to run a cron job every minute. We learned about the syntax of the cron command and how to set it up to run a command or script every minute. We also discussed some troubleshooting steps to take if the cron job is not running as expected. Cron is a powerful tool that can save time and automate repetitive tasks, and knowing how to use it effectively can make system administration much easier.

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