Re: Better battery info/status files

James Sutherland (jas88@cam.ac.uk)
Sun, 4 Feb 2001 16:46:30 +0000 (GMT)


On Mon, 5 Feb 2001, Steve Underwood wrote:
> James Sutherland wrote:
> > On Sun, 4 Feb 2001, Ben Ford wrote:
> > > David Woodhouse wrote:
> > > > On Sun, 4 Feb 2001, James Sutherland wrote:
> > > >
> > > > > For the end-user, the ability to see readings in other units would be
> > > > > useful - how many people on this list work in litres/metres/kilometres,
> > > > > and how many in gallons/feet/miles? Probably enough in both groups that
> > > > > neither could count as universal...
> > > >
> > > > Yeah. We can have this as part of the locale settings, changable by
> > > > echoing the desired locale string to /proc/sys/kernel/lc_all.
> > >
> > > Just an idea, . . but isn't this something better done in userland?
> > >
> > > (ben@Deacon)-(06:49am Sun Feb 4)-(ben)
> > > $ date +%s
> > > 981298161
> > > (ben@Deacon)-(06:49am Sun Feb 4)-(ben)
> > > $ date +%c
> > > Sun Feb 4 06:49:24 2001
> >
> > That's what I'd do, anyway - /dev/pieceofstring would return the length of
> > said piece of string in some units, explicityly stated. (e.g. "5m" or
> > "15ft").
> >
> > "uname -s" ("how long's a piece of string on this system") would then
> > convert the length into feet, metres or fathoms, depending on what the
> > user prefers.
>
> Don't get carried away. In the present context we are only talking about
> time and electrical measurements. Whilst most of the human race can't
> read the English labels in /proc, they all use the same measurements for
> electrical units and time (unless the time exceeds 24 hours, where dates
> get a bit screwed up). In this case even the US in in line with the rest
> of humanity............. or would you like to be able to express battery
> capacity in BTUs?

Personally, I'd prefer a percentage and/or estimated time remaining
anyway... However, from the kernel's PoV, the rule is just "KISS". Print
in something consistent, let userspace do any conversions you
want. Probably seconds for time (simplest - scripts can compare "if
est_batterylife_remaining < 300 do something", UI things can convert to
H:M:S or whatever), watts for power.

What is measured, BTW - battery voltage, presumably, and drain
current?

James.

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