Linux shell if powerful tool.
For instance here you can see how with single command nc you can scan ports, make chat server, transfer files, stream video etc http://mylinuxbook.com/linux-netcat-command/#
Here http://flux242.blogspot.com/2011/06/simple-bash-irc-loggin-bot.html you can see IRC logger bot made again using just shell script.
Bash guide for beginners will teach you for the basics of Shell script.
EDIT: the book URL is here: http://tille.garrels.be/training/bash/pr01s03.html :)