With npm, do:
npm install irc-historian -g
or clone this project on github:
git clone http://github.com/kkoenig/irc-historian.git
Gets all the chat messages that occurred while the current user was not present in the given channel.
/message historian update <channel>
Gets the last n chat messages
/message historian get <channel> <n>
join a new channel
/message historian join <channel>