Enter vim ~/update.sh, and edit the ~/update.sh file as shown following, and then write and quit:

Execute the convenience bash file ~/update.sh as depicted following:

pi@Mst0:~ $ bash ~/update.sh ç bash execution command.

Enter vim ~/upgrade.sh, and edit the ~/upgrade.sh file as shown following, and then write and quit:

Execute the convenience bash file ~/upgrade.sh as depicted here:

pi@Mst0:~ $ bash ~/upgrade.sh ç bash execution command.

Enter vim ~/shutdown.sh, and edit the ~/shutdown.sh file as shown following, and then write and quit:

Execute the convenience bash file ~/shutdown.sh as depicted here:

pi@Mst0:~ $ bash ~/shutdown.sh ç bash execution command.

Enter vim ~/reboot.sh, and edit the ~/reboot.sh file as shown following, and then write and quit:

Execute the convenience bash file ~/reboot.sh as depicted here:

pi@Mst0:~ $ bash ~/reboot.sh ç bash execution command. Enter vim ~/ssh.sh, and edit the ~/ssh.sh file as shown following:

Execute the convenience bash file ~/ssh.sh as depicted here:

pi@Mst0:~ $ bash ~/ssh.sh ç bash execution command.

Now that you have at your disposal a very muscular 32 or 64 core Pi2 or Pi3 supercomputer, go show-off its immense processing power by, once again, resolving the integral π equation you've been experimenting with, only this time use 1,000,000 iterations instead of 300,000. Note the change in the π accuracy, and execution time. One million iterations on the restrained 16-node Pi3, takes 23m35.096s to complete, and 0m11.381s (unrestrained), please see code fragment as shown following.

Note that 1,000,000 iterations on the Pi2 (restrained) takes considerably longer for a solution, and only seconds in the unrestrained mode. The author threw the full 76.8 GHz processing power of his Pi3 at the π equation using 5,000,000 iterations (restrained). It took 7.611hrs. of processing time - a rather rigorous exercise for the Pi3 supercomputer - to generate a very accurate π value.