How To Create Scheduled Jobs With Crontab in Linux

Hi everyone!

In this article, I want to talk about cronjob. Some of us heard about this subject before. Cronjob scheduled task used in the sense of is very important for us. Because you can use it everytime you have to set some scripts will run next date. So, imagine that you have got a web site there are so many users on it. If you want to send e-mail to all your members at 02:00 am, here is the time you need cronjob!

Some hosting companies offer to manage cronjob service, but not all. Because of it is every hosting have not CPanel. Maybe you can use SSH or something else. Me, show you how to manage cronjob using SSH. In this regard, open your Unix Server using SSH, and;

vi /etc/crontab

* * * * * ( [minute] [hour] [day] [month] [day of the week] )
┬ ┬ ┬ ┬ ┬
│ │ │ │ │
│ │ │ │ │
│ │ │ │ └───── day of the week (0 – 7) (total 7 days)
│ │ │ └────────── month (1 – 12)
│ │ └─────────────── day (1 – 31)
│ └──────────────────── hour (0 – 23)
└───────────────────────── minute (0 – 59)

//test.php file
$db->query("INSERT INTO db_name.table_name(field_name) values('test')");
 
#cronjob file
* * * * * username php test.php

The code given above shows us the script that adds data to the database every minutes.

*/15 * * * * username php test.php

The code given above also shows us the script that adds data to the database every 15 minutes.

#02:00am at night
00 02 * * * username php test.php
 
#every 3 hours during the day
0 */3 * * * username php test.php
 
#each hour
0 * * * * username php test.php
 
#4 pm o'clock on the 15th day of each month
00 16 15 * * username php test.php
 
#weeks every night at 2 am
00 02 * * 1-5 username php test.php
 
#every hour every Sunday
0 * * * sun
 
#every 3 hours
0 2,5,8,11,14,17,20,23 * * * username php test.php

The codes given above shows us different cronjob examples. You can try and work for creative and usefull cronjob examples.
We'll see you guys next article!