#!/bin/bash

if [[ -r /bin/cygwin1.dll ]]; then
    # in cygwin
    PSF='-ef'
else
    PSF='-efww'
fi

export DISPLAY=:0

# no message if one is displayed already
if [[ "$(ps $PSF | grep gxmessage | grep -v grep)" != "" ]]; then
    exit
fi
# no message if xscreensaver active
if [ "$(ps $PSF | grep xscreensaver | grep -v grep)" != "" ]; then
    exit
fi
# no message if gnome-screensaver active
if [ "$(gnome-screensaver-command --query 2>/dev/null | grep is.active)" != "" ]; then
    exit
fi

gxmessage 'Rest your eyes!'