====== Application ======

I wanted to have a web application through which I can access my sockets through a computer or iPad. The following components make this possible:
  * Apache web server with PHP5, see [[deb720:apache|Apache2 Web Server]]
  * Cron
  * The SQLite3 library, consisting of PHP files only, and myLiteAdmin.php to administer the database
  * Some custom PHP code
  * A daemon written in C++ utilizing the wiringPi and RCSwitch libraries, see [[rpi:gpio|Access to GPIO]]

===== Custom PHP code =====

===== SQLite3 library =====

===== Daemon =====

First, develop and trouble shoot the daemon binary.

==== Check the daemon ====

Start the daemon, then find it's process id (pid):
  $ ps -ax | grep <daemon>

Find all open files:
  # lsof -p <pid>

==== Create the init script ====

On Debian systems, copy the skeleton file and modify to your needs. This is quite simple and straight forward.
  # cp /etc/init.d/skeleton ~/scripts/<daemon>
  # vim <daemon>

==== Install the daemon ====

Copy the binary file:
  # cp ~/binaries/<daemon> /usr/sbin

Copy the script:
  # cp ~/scripts/<daemon> /etc/init.d

Add the daemon to the different run-levels:
  # update-rc.d <daemon> defaults

Remove the daemon from the different run-levels:
  # update-rc.d -f <daemon> remove

See [[https://wiki.debian.org/Daemon|Daemon]] and [[https://wiki.debian.org/LSBInitScripts|LSBInitScripts]] for more details.

===== Cron =====

Run <code> crontab -e</code> and enter the following lines:<code>
*/5 * * * * wget http://localhost/path/to/web/code/state-machine.php
* 14 * * * wget http://localhost/path/to/web/code/randomize.php</code>

The first line will run the state machine every 5 minutes. The second line will randomize your on / off pattern every day at 14:00.