Run a command on boot

= Run commands at boot = To start scripts or commands at startup or shutdown place them in /etc/local.d and suffix them with .start or .stop.

Example
for example to show "Hello World" while add following file: /etc/local.d/HelloWorld.start and make the file executable:

Explanation
The rc-script "local" executes the scripts in alphabetical order after all other services have been started. Check if local is in your runlevel: local |     default minimal quiet
 * 1) rc-update  | grep local

previous Method
Since OpenRC /etc/conf.d/local.start and local.stop are deprecated. To migrate to OpenRC, move them to /etc/local.d.

Using local_start and local_stop function in /etc/conf.d/local is also deprecated. To migrate, move the code to scripts with an according .start or .stop extension in /etc/local.d

more info: http://www.gentoo.org/doc/en/openrc-migration.xml