Note: this post is just a note to myself so I do not forget how to enable UTF-8 in FreeBSD.
I have not realized until today that FreeBSD does not enable UTF-8 by default, even though it is capable. I joined some IRC channels with German speakers some time ago and I always knew there was something wrong in the encoding but I was too lazy to fix it.
Today I had a few minutes to play with the settings in my Screen/Irssi configuration and I could not manage to make it work It is really frustrating... In fact, it was only working when UTF-8 was disabled in Screen, that is a good symptom.
After wondering for a while, a thought it could be the case that the problem comes from the locales, because (in theory) UTF-8 should be enabled everywhere. No!! It was not enabled in my FreeBSD box at home. Searching in Google I found this post explaining the steps.
The charset has to be enabled during the login process. This means we have to change /etc/login.conf or ~/.login_conf . Since I am only interested in having UTF support in the account running Irssi, I made the change there instead of making a global change.
The config is so easy. Edit .login_conf in your Home directory.
Once this is done, it will only apply to new login sessions, so you have to exit Irssi and also close the Screen session.