unset LC_ALL
LC_CTYPE=de_DE.ISO8859-1
export LC_CTYPE

c1=e
# o umlaut
c2=$(printf '\366')
# non-break space
c3=$(printf '\240')
c4=$(printf '\240')
# $c2$c3$c4 form one utf-8 character

ok=0
case $c1$c2$c3$c4 in
*) ok=1 ;;
esac
if [ $ok = 0 ]; then
	echo wrong at $LINENO
	exit 3
fi

case $c1$c2$c3$c4 in
$c1$c2$c3$c4) ;;
*) echo wrong at $LINENO ;;
esac

case $c1$c2$c3$c4 in
"$c1$c2$c3$c4") ;;
*) echo wrong at $LINENO ;;
esac

case $c1$c2$c3$c4 in
????) ;;
*) echo wrong at $LINENO ;;
esac

case $c1$c2$c3$c4 in
[!$c2][!b][!c][!d]) ;;
*) echo wrong at $LINENO ;;
esac

case $c1$c2$c3$c4 in
[$c1][$c2][$c3][$c4]) ;;
*) echo wrong at $LINENO ;;
esac

case $c1$c2$c3$c4 in
["$c1"]["$c2"]["$c3"]["$c4"]) ;;
*) echo wrong at $LINENO ;;
esac