#!/bin/sh
# setres -- sets screen resolution for the X11 window system by reading
#           settings from the kernel command line
#
#           this script was written in a way that allows easy adaptation to
#           other tasks. it is designed to move different configfiles into
#           place dependant on settings supplied at boot-time via the kernel
#           command line (see `cat /proc/cmdline` and your bootloader config).
#
# === SETUP ===
# this script should be used as an initscript in /etc/init.d/ and 
# thus called by the system when entering the appropriate runlevels.
# configure your system to run it in runlevel 5 *before*  X11 is started.
#
# note : you can use the `update-rc.d`-script under debian(-based) systems
#        to set this up like this: `update-rc.d setres start 11 5`.
#
# === USAGE ===
# this script reads the envvar $USEDISPLAY which should be defined on 
# the kernel command line in the usual 'var=value' syntax.
# hint : set this up permanently in your bootloader. an example line for
#        the grub configfile /boot/grub/menu.lst follows :
#
#   kernel /boot/linux-2.6.18.2 root=/dev/hda1 USEDISPLAY=external
#
# written by spirit, see http://www.sp1r1t.org/contact/
# license : this this is public domain => no copyrights, no shit, no warranty
#           (do whatever you want but don't blame me for what you do.)
#


##### user settings - please adapt to your needs #####

## the modes we implement (possible contents of the environment varibable)
MODEA="internal"
MODEB="external"

## the config files you may want to be moved
CONFIG_USEDBYSRV="/etc/X11/XF86Config-4"
CONFIG_MODEA="/etc/X11/XF86Config-4.internal"
CONFIG_MODEB="/etc/X11/XF86Config-4.external"
CONFIG_DEFAULT="/etc/X11/XF86Config-4.internal"
CONFIG_BACKUP="/etc/X11/XF86Config-4.backup-by-setres"



##### other settings - you should not need to change these #####

## name of this application
NAME="setres"
ENVVAR_NAME="\$USEDISPLAY"

## paths to some applications we use
LOGGER="/usr/bin/logger -p user.info -t $NAME"
CP="/bin/cp"
ECHO="/bin/echo"


##### here we go - don't ouch anything below this line unless you know what you're doing #####

## react to (or at least pretend to do so) stuff initscripts should react to
case "$1" in
    start|restart|reload|force-reload)
	
	## check for required files
	$ECHO "$NAME: checking for required files..."
	if [ ! -f "$CONFIG_MODEA" ]; then $ECHO "$NAME: ERROR: $CONFIG_MODEA not found" && exit 0; fi
	if [ ! -f "$CONFIG_MODEB" ]; then $ECHO "$NAME: ERROR: $CONFIG_MODEB not found" && exit 0; fi
	if [ ! -f "$CONFIG_DEFAULT" ]; then $ECHO "$NAME: ERROR: $CONFIG_DEFAULT not found" && exit 0; fi
	$ECHO "$NAME: all files seem to be there."

	## check contents of variable supplied to us via kernel command line
	$ECHO "$NAME: reading settings from environment variable $ENVVAR_NAME: $USEDISPLAY"
	case "$USEDISPLAY" in
    		$MODEA)
                    $CP $CONFIG_USEDBYSRV $CONFIG_BACKUP
                    $CP $CONFIG_MODEA $CONFIG_USEDBYSRV
                    $ECHO "$NAME: configuring your system for mode $MODEA"
                    $LOGGER "$NAME: configuring your system for mode $MODEA"
                    ;;
					 
	    	$MODEB)
                    $CP $CONFIG_USEDBYSRV $CONFIG_BACKUP
                    $CP $CONFIG_MODEB $CONFIG_USEDBYSRV
                    $ECHO "$NAME: configuring you system for mode $MODEB"
                    $LOGGER "$NAME: configuring you system for mode $MODEB"
                    ;;
		 
    		*)
                    $CP $CONFIG_USEDBYSRV $CONFIG_BACKUP
                    $CP $CONFIG_DEFAULT $CONFIG_USEDBYSRV
		    $ECHO "$NAME: WARNING: nothing suitable found in environment variable $ENVVAR_NAME."
                    $ECHO "$NAME: WARNING: configuring your system for mode default"
		    $LOGGER "$NAME: WARNING: nothing suitable found in environment variable $ENVVAR_NAME."
                    $LOGGER "$NAME: WARNING: configuring your system for mode default"
                    ;;
	esac
	;;
	
    stop)
	$ECHO "$NAME: nothing to stop here."
	;;
    manual)
	case "$2" in
    		$MODEA)
                    $CP $CONFIG_USEDBYSRV $CONFIG_BACKUP
                    $CP $CONFIG_MODEA $CONFIG_USEDBYSRV
                    $ECHO "$NAME: manual mode: configuring your system for mode $MODEA"
                    ;;
					 
	    	$MODEB)
                    $CP $CONFIG_USEDBYSRV $CONFIG_BACKUP
                    $CP $CONFIG_MODEB $CONFIG_USEDBYSRV
                    $ECHO "$NAME: manual mode: configuring your system for mode $MODEB"
                    ;;
		 
    		*)
                    $ECHO "$NAME: manual mode: usage: $NAME manual {$MODEA|$MODEB}'"
                    ;;
	esac
	;;
    *)
	$ECHO "$NAME: don't know what to do, sorry. remember : i'm an init-script!"
	$ECHO "$NAME: usage : '$NAME {start|restart|reload|force-reload|stop}'"
	$ECHO "$NAME: usually this is what you want : '$NAME start'"
	$ECHO "$NAME:" 
	$ECHO "$NAME: to make me ignore the environment variable $ENVVAR_NAME and invoke"
	$ECHO "$NAME: me manually type : '$NAME manual {$MODEA|$MODEB}'"
	$ECHO "$NAME: open me in a text editor for more info."
	;;
esac
$ECHO "$NAME: done, exiting."
exit 1