cleanname now uses perl-rename and works

.local/bin/etc/cleanname

@@ -1,3 +1,3 @@
 #!/bin/sh
 [ -z "$1" ] && (echo "Error: missing argument (what to remain)" && exit)
-rename 'y/[A-Z]/[a-z]/; s/Ö/oe/; s/Ä/ae/; s/Ü/ue/; s/ß/ss/' $1
+perl-rename 's/\ /_/g; y/[A-Z]/[a-z]/; s/Ö/oe/g; s/ö/oe/g; s/Ä/ae/g; s/ä/ae/g; s/Ü/ue/g; s/ü/ue/g; s/ß/ss/g' "$1"