I have this machine that has a single unicode character (a monkey) as it's hostname.. In the past this has worked quite well but now syslogd doesn't log anything at all. I am not 100% sure when the regression happened, but I suspect it was around February this year. Turning on the debug-flag I see the screen filling up with: Failed to parse HOSTNAME from and then every single line of output that should have been logged. I suspect this might happen to anybody that has a funky character in their hostname.
Which exactly character (code) is the problem?
(In reply to Yuri Pankov from comment #1) 🐒
(In reply to Sverre from comment #2) The hostname is 🐒.domain.blah
Actually it seems that it's enough to have some emoji char in your hostname - it doesn't have to be all emoji... so awef🐒awef.domain.blah will also make syslogd fail to log... I think it's the part where it strips out "dangerous characters" that is the culprit,.. Compiling a version without that check now to see if that works.
It doesn't actually have to be an emoji either.. ℬ, ⨊, ... even the norwegian letters like å,æ,ø makes it fail.. and the swedish variants ä, ö .. It's a nice way to disable all logging if you got root on a box: just switch your hostname to something that has a weird character in it and there is basically no trace of anything you do on it.