#!/bin/sh
#
#!F:switch_kernel
#
#!P:/usr/local/sbin
#
#!D:Kernel 2.0/2.1/2.2/2.3 depended link switcher
#
#!I:Should be called by /etc/init.d/rc.sysinit after mounting
#!I: the filesystems
#!I:Following files are supported at the moment:
#!I: /etc/conf.modules (because some module names/information differs)
#!I: /etc/printcap (because the lpx assign mechanism has changed)
#
#!C:Copyright 1998-1999 Peter Bieringer <pb@bieringer.de>
#
#!V:Version 1.20 1999-01-19
#
# Changes to
#  1.20: New running scheme
#  1.12: Minor fix
#  1.11: Now also for kernel 2.3 (for the future)
#  1.10: Now also for kernel 2.2
#        Changing of the filenames
#  1.01: Stand-alone version


### Info for switching configuration files

## modules configuration

# Switching /etc/conf.modules enabled?
MODULES_SWITCH=yes

# Filenames
MODULES_20=/etc/conf.modules-2.0
MODULES_21=/etc/conf.modules-2.1
MODULES_22=/etc/conf.modules-2.2
MODULES_23=/etc/conf.modules-2.3
MODULES_ORIG=/etc/conf.modules


## printcap

# Switching /etc/printcap enabled?
PRINTCAP_SWITCH=yes

# Filenames
PRINTCAP_20=/etc/printcap-2.0
PRINTCAP_21=/etc/printcap-2.1
PRINTCAP_22=/etc/printcap-2.2
PRINTCAP_23=/etc/printcap-2.3
PRINTCAP_ORIG=/etc/printcap



## Functions

# Display information
info() {
  grep "^#!D" $0 | awk -F: '{ print $2}'
  grep "^#!C" $0 | awk -F: '{ print " " $2}'
  grep "^#!V" $0 | awk -F: '{ print " " $2}'
}
    
usage() {
    echo "Syntax: switch_kernel {2.0|2.1|2.2|2.3|auto}"
    exit 1
}
    

### Start

info

if [ "$1" = "auto" ]; then
    KERNELVERSION=`cat /proc/version | awk '{ print $3 }' | awk -F. '{ print $1 "." $2 }'`
    echo "  Automatic detected kernel version is '$KERNELVERSION'"
else
    if [ "$1" != "" ]; then
        KERNELVERSION=$1
    else
	usage
    fi
fi


## Get version depending files

case $KERNELVERSION in
    2.0)
	MODULES_NEW=$MODULES_20
	PRINTCAP_NEW=$PRINTCAP_20
	;;
    2.1)
	MODULES_NEW=$MODULES_21
	PRINTCAP_NEW=$PRINTCAP_21
	;;
    2.2)
	MODULES_NEW=$MODULES_22
	PRINTCAP_NEW=$PRINTCAP_22
	;;
    2.3)
	MODULES_NEW=$MODULES_23
	PRINTCAP_NEW=$PRINTCAP_23
	;;
    *)
	usage
	;;
esac


## Test if new file exists

if [ "$MODULES_SWITCH" = "yes" ]; then
    if [ ! -f $MODULES_NEW ]; then
	echo "  File '$MODULES_NEW' doesn't exist!"
	MODULES_SWITCH="no"
    fi
fi

if [ "$PRINTCAP_SWITCH" = "yes" ]; then
    if [ ! -f $PRINTCAP_NEW ]; then
	echo "  File '$PRINTCAP_NEW' doesn't exist!"
	PRINTCAP_SWITCH="no"
    fi
fi

    
## Now do the work

if [ "$MODULES_SWITCH" = "yes" ]; then
    # Change softlink to a conf.modules,
    #  which has specific entries             	
    
    # Make backup of the existing file, if not a link
    if [ -f $MODULES_ORIG -a ! -L $MODULES_ORIG ]; then
	mv -bV t $MODULES_ORIG $MODULES_ORIG.bak
    fi
	    
    echo "  Link '$MODULES_ORIG' to '$MODULES_NEW' for $KERNELVERSION.x usage."
  
    # Create new or change link	
    ln -f -s $MODULES_NEW $MODULES_ORIG
fi
	

if [ "$PRINTCAP_SWITCH" = "yes" ]; then
    # Change softlink to a printcap,
    #  which has specific entries             	

    # Make backup of the existing file, if not a link
    if [ -f $PRINTCAP_ORIG -a ! -L $PRINTCAP_ORIG ]; then
	mv -bV t $PRINTCAP_ORIG $PRINTCAP_ORIG.bak
    fi
	    
    echo "  Link '$PRINTCAP_ORIG' to '$PRINTCAP_NEW' for $KERNELVERSION.x usage."
    # Create new or change link	
    ln -f -s $PRINTCAP_NEW $PRINTCAP_ORIG
fi

exit 0