Something

REVISION=$(svn update | tail -n 1 | awk '{print $NF}' | tr  -d '.')
OLDREVISION=$(cat .revision)

if [ $REVISION -eq $OLDREVISION ]; then
        echo "SVN remains at ${REVISION}. Not building."
        if [ -f ../inkscape_0.46.0-svn+${REVISION}_$(arch).deb ]; then
                echo "Install ../inkscape_0.46.0-svn+${REVISION}_$(arch).deb"
        fi
        exit
else
        echo "Updated from ${OLDREVISION} to ${REVISION}, building."
        echo $REVISION > .revision
fi

# Run autogen, just to make sure we don't try to build things that were removed.
#
./autogen.sh > /dev/null 2>&1

dch -D gutsy -v "0.46.0-svn+$REVISION" "New svn auto-build."

PACKAGE=$(fakeroot dpkg-buildpackage -b 2>&1 | grep "dpkg-deb: building package" | awk -F '/' '{print $2}' | sed "s/'\.//g")
echo "Finished building package /usr/src/${PACKAGE}"