xbrightness: xbrightness (adjusts brightness of the X server display)
xbrightness:
xbrightness: xbrightness sets the overall brightness of a monitor via the XFree86
xbrightness: X server video mode extension (XFree86-VidMod-Extension).
xbrightness:
xbrightness: It uses the XF86VidModeSetGammaRamp function, which provides a
xbrightness: more flexible control than the old XF86VidMode-SetGamma. The latter
xbrightness: function cannot change the endpoints of the gamma curve, only the
xbrightness: middle, so full brightness remains full brightness no matter how you
xbrightness: set the gamma.
xbrightness: