sub URI_ESCAPE {
        my ($text) = @_;
        return undef unless defined $text;
        my (%escapes);
        for (0..255) { $escapes{chr($_)} = sprintf("%%%02X", $_) }
        $text =~ s/([^;\/?:@&=+\$,A-Za-z0-9\-_.!~*'()])/$escapes{$1}/g;
        $text;
}

my $orig = 'hallo äther';
print "$orig wird zu " . URI_ESCAPE ($orig);