Just want to be able to automate with command line / bash scripts
joining (concantening) audio ogg files together

Thread below does not have a solution: MP3/Ogg joiner?
http://forums.macrumors.com/archive/.../t-121537.html

I tried just cat, but this make very ugly files
ogmcat doc says "ogmcat does NOT work at the moment"
(although I tried with 2 small files, and seems ok...)

I am happy to use flac or another format (but not wav), provided I can do
command line concatenation.

Any suggestions? Sorry my google attempts did not find anything for linux,
and ogg concatenation did not show anything in LQ
Thanks in advance

You might look into sox. It's the swiss army knife of command-line audio editors. I believe it can cat multiple files if they all have the same data structure.

I'm wondering if the reason cat didn't work right might have something to do with metadata tags. If you have any tags in the file, then it would probably sandwich them in inbetween the audio data.