Re: Using JS to write to file under /sys

[Alessandro Crismani <alessandro crismani gmail com>]

Il 27/07/2012 01:04, Alessandro Crismani ha scritto:
> but I get an error that sounds like:
>
> root at alessandro-sammy in /data/Documenti/Linux/SammySettings
> # LC_ALL=C gjs SammySettings.js
>      JS ERROR: !!!   Exception was: Error: Error invoking
> GLib.file_set_contents: Failed to create file
> '/sys/devices/platform/samsung/battery_life_extender.ZTDFIW': No such
> file or directory
>      JS ERROR: !!!     lineNumber = '0'
>      JS ERROR: !!!     fileName = '"gjs_throw"'
>      JS ERROR: !!!     stack = '"("Error invoking
> GLib.file_set_contents: Failed to create file
> '/sys/devices/platform/samsung/battery_life_extender.ZTDFIW': No such
> file or directory")@gjs_throw:0
> ([object _private_Gtk_Switch],[object
> _private_GObject_ParamSpec])@SammySettings.js:108
> wrapper([object _private_Gtk_Switch],[object
> _private_GObject_ParamSpec])@/usr/share/gjs-1.0/lang.js:204
> @SammySettings.js:146
> "'
>      JS ERROR: !!!     message = '"Error invoking
> GLib.file_set_contents: Failed to create file
> '/sys/devices/platform/samsung/battery_life_extender.ZTDFIW': No such
> file or directory"'

Ok, I guess that file because it tries to create a temp file and then 
replace the original one with it. That doesn't work under /sys.

I also tried something like:
        let _batteryGFile = Gio.file_new_for_path(batteryFile);
        let _batteryOut = _batteryGFile.replace(null, false, 
Gio.FileCreateFlags.NONE, null);
        let _batteryStream = new Gio.DataOutputStream({ base_stream: 
_batteryOut});
        _batteryStream.put_string("1", null);
        _batteryStream.close(null);

But it throws an error too:
	JS ERROR: !!!     message = '"Error invoking Gio.close: Error writing 
to file: Invalid argument"'

Both solutions work when I try to write a file in my home, hence they 
should be ok from the tpo pint of view.

I am thinking of spawning a damn "echo 1" and get the work done, but it 
seems to be *horribly* bad. Anyone has a better idea? How am I supposed 
to change such config files according to some good programming rules?

Thanks a lot!
Alessandro