How to enable and use rc.local in Ubuntu?

In Ubuntu, the rc.local file is disabled by default. If you need to enable and use the rc.local file, you can follow the steps below:

1. Open the terminal and enter the following command to open the rc.local file for editing:

sudo nano /etc/rc.local

1. Add the commands or scripts that you want to run automatically when the system starts in the rc.local file. For example, you can include the following:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
  printf "My IP address is %s\n" "$_IP"
fi

exit 0

1. Save and exit the rc.local file. In the nano editor, press Ctrl+X, then press Y to confirm saving, and finally press Enter to confirm the file name.
2. To grant execution permissions to the rc.local file, enter the following command:

sudo chmod +x /etc/rc.local

1. Finally, restart the system to apply the changes by entering the following command:

sudo reboot

Afterwards, when the system starts up, the commands or scripts added in the rc.local file will be executed automatically.