Fix cylinder printout information

[Dirk Hohndel]

Linus Torvalds <torvalds at linux-foundation.org> writes:
> This also fixes things so that in the absence of cylinder size
> information, it prints the pressure difference, not just zero.
>
> Also I have no idea how metric people want to get the air usage. Anybody?
>
> The choices are:
>
>  - wet size, the same way as  (which would require working pressure of
> the cylinder in order to calculate), ie if you have a 12l cylinder, it
> would say "8l" if you used two-thirds of the gas.
>
>  - "air volume at one ATM" (the same way imperial people show cylinder
> information)
>
> I'm assuming the latter, because that seemed to be what Salvador was
> approximating (except he turned the pressure difference into bar, not
> ATM). Also, metric cylinders don't necessarily have a saved working
> pressure, so..

Yes, I think the latter is what people are looking for (how many liters
of air at 1atm they consumed).

Why would you need a working pressure to do that if you have a wet
volume. I'm missing something here...

BTW: I notice that we are printing OTUs and CNS... wouldn't it be even
more interesting to print the SAC rate above those two? 


Pushed.

/D