Writing a custom daemon

In this last section, we'll learn how to write our own daemon in several programming languages using a skeleton that can be used to quickly develop really complex daemons. Due to the lack of space, we cannot add all the possible features a daemon has, but the presented skeletons will have whatever you need to know about daemon creation.

All example code will implement a daemon with the following command line usage:

usage: mydaemon [-h] [-d] [-f] [-l]
-h    - show this message
-d    - enable debugging messages
-f    - do not daemonize
-l    - log on stderr

The -h option argument will show the help message, while -d will enable the debugging messages. The -f option argument will prevent the daemon from running in the background, and the -l option will print the logging messages to the standard error channel. Apart from the -h option argument, the other arguments are very useful during the debugging stages if used together in the form:

# ./mydaemon -d -f -l

The developer...