NAME

       xphoon - displays the PHase of the mOON on the root window

SYNOPSIS

       xphoon [-b] [-t interval [-i]] [-s] [-display name]

DESCRIPTION

       Xphoon sets the X root window to a picture of the moon in its current phase, including the
       partial lighting of the dark side by reflected earthlight.

OPTIONS

       -b     Defeats the earthlight feature, forcing the dark side to be black.

       -t     Have xphoon keep running and update the picture every interval minutes.  (Normally,
              xphoon just sets the root picture and exits.)

       -i     Forks a background process and prints the process-id to stdout.  Useful if you want
              to make menu commands to refresh or kill xphoon.

       -s     Rotate the whole picture 180 degrees, resulting in a moon picture as viewed fom the
              Southern hemisphere.

       -demo  Demonstrate xphoon by rapidly stepping through moon phases.

NOTES

       The  original motivation for this program was that xsetroot was too slow.  Loading a full-
       screen bitmap took about 15 seconds.  We made a trivial program that  had  fullmoon.bitmap
       compiled  in,  and  it  ran  in less than a second.  (And incidentally, the executable was
       smaller than fullmoon.xbm.)  Then later we came up with the phase hacking, the earthlight,
       and the auto-scaling.

SEE ALSO

       phoon(1), xsetroot(1)

AUTHORS

       Copyright (C) 1988, 1991 by Jef Poskanzer and Craig Leres.

       The moon-phase computation is from "moontool.c" by John Walker.

                                           6 April 1999                                 xphoon(6)