#TIL that there is a command "units" for units conversion exists. In the #BSD world it was appeared in the #NetBSD then ported to the #FreeBSD 2.2.0, according to the "History" section in the manpage.

https://jlsksr.de/notes/24100102/

At least, for now I known that 19 liters equals to 30.89 vodka bottles, or 154.47 charkas (чарок, от «чарка»), or 308.94 shkalikoff (шкаликов, от «шкалик»), or 1.55 vёder (вёдер, от «ведро»).

Conversion rules lives in the simple text file in the /usr/share/misc/definitions.units and the own rules could be written in some text file in the same manner.

@rf