NAME

       brightd - a brightness control daemon

SYNOPSIS

       brightd [-v] [-d] [-P <file>] [-u n] [-e n] [-w n] [-b s] [-f] [-c n] [-x] [-r n]

DESCRIPTION

       brightd  is  a daemon which dynamically reduces LCD brightness when you don't use your pc.
       The idea is adapted from iBooks.

OPTIONS

       -v     Output some debugging information. Will not work in daemon mode.

       -d     Will cause brightd to fork itself into background.  You'll want to use this ;)

       -P <file>
              Set location of pid file in daemon mode (Default is /var/run/brightd.pid).

       -u n   brightd will drop privileges after opening all file descriptors. With this  setting
              you may choose which user to change to.

              You have to start brightd as root; or at least as a user which might as well access
              X11-Sessions and /dev/input/event

       -e n   Filter  used  event  sources  by  POSIX  extended  regexp  n  (for   example,   use
              "i8042.+event" on intel platforms to avoid having HDAPS taken into account) You are
              supposed to include "event" here, but you are not required to.

       -w n   The amount of seconds of inactivity to wait before reducing brightness

       -b n   Dark screen brightness Never reduce brightness below that  value.   Note  that  you
              won't be able to change brightness manually below this value as well.

       -f     Reduce  brightness  even  if  on the highest brightness level.  By default, brightd
              won't do this. That way you can temporally disable it while reading through a  text
              or  so.  If you specify this option twice, brightd will also reduce brightness when
              you're on AC.

       -c s   Set  the  backlight  class  to  use.   You   may   specify   any   subdirectoy   of
              /sys/class/backlight

       -x     Don't query X11 for inactivity / deactivated screensavers

       -r n   brightd  will  create  a  FIFO n (deleting the file if it existed before!) and read
              from it. If you tell your acpid to write brightness levels to that  FIFO  when  the
              user  changes  brightness,  brightd  can  help you with some stuff: For example, if
              brightd  faded  to  brightness  0  and  you  increase  brightness,  brightd   would
              automatically fade up to the highest level.

FILES

       /usr/bin/brightd /sys/class/backlight/*/*

AUTHORS

       Phillip Berndt (mail at pberndt dot com)
       Richard Weinberger (richard at nod dot at)
       Hannes von Haugwitz (hannes at vonhaugwitz dot com)