SSH | Add a Cron Job

A corn is a time based job scheduler which runs automatically on unix-like server. It is use to schedule jobs or tasks to runs at fixted date, time or intervas.

for conducting a corn job in unix-like server. we need putty or ssh which is a secure shell or terminal emulator. this is use to access remote systems over the internet.

Step 1

You need to connect your server via SSH. You can follow this guide on how to connect your server via SSH.

To display the on-line help for crontab enter:

man crontab

Step 2

Type crontab -e and press enter to get access to your server crontab.To make it editable, just press the “insert” button on keyboard.

crontab -e

Info: A crontab is a simple text file in your server which contain a list of commands meant to be run at fixted times.

Step 3

Now you can add or edit your cron jobs or schedules.

Before you start, lets have a look on the cron jobs formate.

┌───────────── min (0 – 59)

│ ┌────────────── hour (0 – 23)

│ │ ┌─────────────── day of month (1 – 31)

│ │ │ ┌──────────────── month (1 – 12)

│ │ │ │ ┌─ day of week (0 – 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat)

│ │ │ │ │

* * * * *  /path/to/your/script.sh

* * * * * => Run every minute
0 * * * * => Run every Hour
0 0 * * * => Run every midnight
0 0 0 * * => Run every Month
0 0 0 0 * => Run every Weekdays

Step 4

After you’re done editing, press the “Esc” key on your keyboard to exit from the edit mode. It will again look like this:

Step 5

To exit cron tab, you should type ":wq"and press enter.