update-xscreensaver-hacks

#!/bin/bash

_SYSCONFDIR=${sysconfdir:-/etc}
_PREFIX=${prefix:-/usr}
_DATADIR=${datadir:-${_PREFIX}/share}

ADDIR=${ADDIR:-${install_prefix}${_SYSCONFDIR}/xscreensaver}
CONFDIR=${CONFDIR:-${install_prefix}${_DATADIR}/xscreensaver/hacks.conf.d}
ADFILE=${ADFILE:-$ADDIR/XScreenSaver.ad}

fix_hackconf ()
{
	if [ ! -s $1 ] ; then
		echo "$1 is empty" >&2
		echo ""
		return 1
	fi

	tmpconf=`mktemp /tmp/hackconf.XXXXXXXX`
	tmpconf_1=`mktemp /tmp/hackconf.XXXXXXXX`
	tmpconf_2=`mktemp /tmp/hackconf.XXXXXXXX`
	tmpconf_3=`mktemp /tmp/hackconf.XXXXXXXX`
	sed -n -e '$p' $1 > $tmpconf_1
	sed -e '$d' $1 > $tmpconf_2
	for file in $tmpconf_1 $tmpconf_2 ; do
		if ( [ -s $file ] && grep -q '\\n\(\|\\\)[^\\].*$' $file ) ; then
			rm -f $tmpconf $tmpconf_1 $tmpconf_2 $tmpconf_3
			echo ""
			echo "ignoring $1" >&2
			return 1
		fi
	done
	if ! grep -q '\\n[\\]*$' $tmpconf_1 ; then
		sed -i -e 's|\(^.*$\)|\1 \\n\\|' $tmpconf_1
	fi
	sed -i -e 's|\\n$|\\n\\|' $tmpconf_1
	while [ -s $tmpconf_2 ] ; do
		sed -n -e '1p' $tmpconf_2 > $tmpconf_3
		sed -i -e '1d' $tmpconf_2
		if ! grep -q '\([ \t]\\$\|\\n\\$\)' $tmpconf_3 ; then
			rm -f $tmpconf $tmpconf_1 $tmpconf_2 $tmpconf_3
			echo ""
			echo "ignoring $1" >&2
			return 1
		fi
		cat $tmpconf_3 >> $tmpconf
	done
	cat $tmpconf_1 >> $tmpconf
	rm -f $tmpconf_1 $tmpconf_2 $tmpconf_3
	echo $tmpconf
	return 0
	
}

for suffix in header tail ; do
	if [ ! -r $ADDIR/XScreenSaver.ad.$suffix ] ; then
		echo "$ADDIR/XScreenSaver.ad.$suffix missing"
		exit 1
	fi
done

tmpfile=`mktemp /tmp/XScreenSaver.ad.XXXXXXXX`

cat > $tmpfile <<EOF
! Don't edit this file directly by yourself!!
! This file is not meant to be edited directly.
!
! Instead, please edit /etc/xscreensaver/XScreenSaver.ad.header,
! /etc/xscreensaver/XScreenSaver.ad.tail and add files under
! /usr/share/xscreensaver/hacks.conf.d if you want.
!
! Then call /usr/sbin/update-xscreensaver-hacks to 
! update this file.
!
EOF

cat $ADDIR/XScreenSaver.ad.header >> $tmpfile

for hackconf in $CONFDIR/*.conf ; do
	hackconf_fixed=`fix_hackconf $hackconf`
	if [ -n "$hackconf_fixed" ] ; then
		cat $hackconf_fixed >> $tmpfile
		rm -f $hackconf_fixed
	fi
done
sed -i -e '$s|\\n\\$|\\n|' $tmpfile

cat $ADDIR/XScreenSaver.ad.tail >> $tmpfile
install -c -p -m 644 $tmpfile $ADFILE
rm -f $tmpfile