How to make a raspberry pi script run up on startup (with example code)

[Naman (Naman Kayastha)]

How to make a raspberry pi script run up on startup

Step 1

Open your terminal and write “crontab -e”, when opened for the first time an editor needs to be selected. For this example we choose nano.

Step 2

After opening nano navigate down to the bottom of the document. Here you will need to write "@reboot python3 " followed by the directory your file is located. If your following this tutorial using nano, you can press ctrl+x to exit the editor, then press ‘y’ to save the edit.

Example

Start a new script and copy the following code

import os
from datetime import datetime
import time

MAX_FILE_SIZE_B = 1024


def log_current_time(log_path):
   now = datetime.now()
   timestamp = now.strftime('%Y-%m-%d_%H-%M-%S')               
   write_mode = 'a'                                            

   if os.path.isfile(log_path):                                
       size = os.path.getsize(log_path)                        
       if size >= MAX_FILE_SIZE_B:                             
           write_mode = 'w'

   with open(log_path, mode=write_mode) as output_file:
       output_file.write(timestamp + '\n')
       print(timestamp)

if __name__ == '__main__':
   log_path = '/home/pi/Desktop/output.txt'

   while True:
       log_current_time(log_path)
       time.sleep(1.0)

Follow the the previous mentioned steps to setup the to start upon boot up.
Now restart the Raspberry pi and navigate to your Destop folder in your files.
Open the file named “output.txt”
Here you will see the current date and time.

Extra

To stop running a script up on bootup, open the crontab. Just remove the line with your script, then close and save the editor. Don’t forget to restart the Raspberry pi.