#!/bin/bash

# restore a virgin environment for public users
# markus@wernig.net 2002-30-04
#
# it will remove all user-writable data from user's home
# directory and then copy all data from a template directory
# back to user's dir.
# 
# this is intended to be called by the logout procedure
# on a UNIX/Linux multiuser machine when a user session ends.
#
# this could be ~/.logout, ~/.bash_logout etc., but since 
# we mostly use X environments, it might be best called
# when a user Xsession is terminated.
#
# xdm provides the $XDMDIR/Xreset for that.
# on my SuSI it is /etc/X11/xdm/Xreset
#
# MINI-HOWTO:
# 1) create user
# 2) set up her environment: configure desktop/windowmanager etc
#    make sure her home is in $HOMEDIR below 
# 3) copy $HOMEDIR to $CLEAN_DIR (here: /home/.clean/$USER)
#    $ cp -raf $HOMEDIR $CLEAN_DIR
# 4) make sure $CLEAN_DIR is not writable by user 
# 5) edit this script. set $LOCAL_USER to the user you want cleared
#                      set $HOMEDIR to directory to be cleared
#                      set $CLEAN_DIR to template directory
# 6) edit Xreset to call this script (and pass it the filename as reference)
#    e.g.: /sbin/userclean Xreset
#    this will depend on your X configuration
#
# have fun and beware!
#

logger -p daemon.warn "Called from $1 by $USER ($LOGNAME)"

cd /home

LOCAL_USER="user"
HOMEDIR="/home/${LOCAL_USER}"
CLEAN_DIR="/home/.clean/${LOCAL_USER}"

DIRCLEAN="true"


# run only if user or root

if ! [ $USER = ${LOCAL_USER} -o $USER = "root" ]; then
	logger -p daemon.warn "attempted to run as $USER instead of ${LOCAL_USER} or root"
	exit 127
fi


# first check if we have a clean template directory

if [ -d "$CLEAN_DIR" ]; then
	
	logger -p daemon.warn "Replacing $HOMEDIR with $CLEAN_DIR"

	# then remove every file in old home

	for rem in `ls -a "$HOMEDIR"`
	do
		if ! [ -w "$HOMEDIR/$rem" ]; then
			continue
		fi
			
		if [ "$rem" = "." -o "$rem" = ".." ]; then
			continue
		fi
		if rm -rf "$HOMEDIR/$rem"; then
			true
		else 
			DIRCLEAN=false
		fi			
	done
	if [ $DIRCLEAN = true ]; then
		logger -p daemon.warn "removed $HOMEDIR/*"
	else
		logger -p daemon.warn "couldn't remove $HOMEDIR/*"
	fi

	# now copy back from template dir

	DIRCLEAN=true
	for rep in `ls -a "$CLEAN_DIR"`
	do
		if [ "$rep" = "." -o "$rep" = ".." ]; then
			continue
		fi

		if cp -raf "$CLEAN_DIR/$rep" "$HOMEDIR"; then
			true
		else 
			DIRCLEAN=false
		fi			
	done

	if [ $DIRCLEAN = true ]; then
		logger -p daemon.warn "replaced $HOMEDIR/*"
	else
		logger -p daemon.warn "couldn't replace $HOMEDIR/*"
	fi
	
	chown -R "$LOCAL_USER" "$HOMEDIR"
#	chown root:root "$HOMEDIR/.xinitrc"
else
	logger -p daemon.warn "$CLEAN_DIR is not a directory"
fi