How to create cron job in ubuntu

In this POST I will show how to create a cron job in Ubuntu. For this we will use python script to print current date and time in log file.

In the previous posts I had shown How to....

• How to Install MongoDB on Ubuntu 16.04
• Failed to start mongod.service unit mongod.service not found. ubuntu 16.04
• How To Install WordPress, Apache, MySQL and PHP on Ubuntu 16.04

OutPut:

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Lets start by creating show_time.py file. copy and paste the below code into the created file.

import datetime

def show_datetime():
    print(datetime.datetime.now())    
    
show_datetime

Now run this python file in the terminal to check expected output.

python home/vara/show_time.py 

Now to Allow this file as Executing program

sudo chmod +x home/vara/show_time.py

Now In the Terminal open cron job with the below command.

sudo crontab -e

Now Copy paste the below code in the cron tab accordingly and save it.

* * * * * /home/vara/show_time.py >> /home/vara/showtime.log 2>&1

The above cronjob will execute automatically for every 1min and writes the out put in the log file.

Here You may get the error as shown

import: unable to open X server `' @ error/import.c/ImportImageCommand/364.
/home/vara/show_time.py: 5: /home/vara/show_time.py: Syntax error: "(" unexpected

To resolve the above error just add #!/usr/bin/env python in 1st line of python file.

#!/usr/bin/env python

import datetime

def show_datetime():
    print(datetime.datetime.now())    
    
show_datetime