tee: use unbuffered stdout

[Ντέντος Σταύρος]

Hello there,

I have tried to both store command output to a file and show it on the
terminal; hence I used `tee`.
However, I noticed that `tee` does heavy input buffering for my liking
(even on several `\n`).

What is worse is, the program I use does provide output without a
trailing `\n`, and, for the sake of this example,
"it is highly important" that I can see also partial output.

If I run the command unpiped to `tee`, then it works fine.

I searched online, however neither `stdbuf` nor `unbuffer` (from
`expect`) are able to help with the case.

Would it be easy enough to add a `--no-buffering` flag to `tee` instead?
Or, is there something else I missed from the internet for such operation?

Ντέντος Σταύρος