Programmatically getting battery status

[Ken Brown]

On 1/10/2018 3:17 PM, Ken Brown wrote:
> On most platforms Emacs is able to display battery status on its mode
> line.  I'd like to try to implement this on Cygwin, but I could use some
> pointers on how to get started and what method would be preferred.
> 
> Emacs uses /proc/apm, /proc/acpi/battery, or /sys/class/power_supply/ on
> Linux; /usr/sbin/apm on BSD; pmset on macOS; and GetSystemPowerStatus on
> Windows.
> 
> What would be the preferred approach on Cygwin?  Based on absolutely no
> knowledge, my instinct would be to use GetSystemPowerStatus to populate
> a suitable file in /proc and/or to write a utility (usr/sbin/apm.exe).
> But I have no specific ideas beyond that.

On second thought, unless people would find this useful for other 
purposes, I may be losing motivation to work on this.  It turns out that 
the Emacs function for getting battery status in the Windows build is 
already built into the Cygwin emacs-w32 build.  It shouldn't be hard to 
make Cygwin's emacs-nox and emacs-X11 use this function also.

Ken