Then, brand_get.php executes "python" command on the system to run the run.py file which appends a new line of string at the end of the data.txt file. Finally, all the content of this text file is ...

But before that, you need to make the script executable. Otherwise, you may get sh: 1: ./system.py: Permission denied. To avoid this, execute the following line of code, then run the PHP file to ...