my @data = (
    qq{key1~key2~key3\nvalue for key1, key2, key3},
    qq{key4~key5~key6\nValue for key4, key5, key6},
    qq{key7~key8~key9\nValue for key7, key8, key9}
);

my %hash;
foreach my $d (@data) {
    my ($key_str, $val_str) = split("\n", $d);
    my @keys = split("~", $key_str);
    @hash{@keys} = ($val_str) x scalar(@keys);
}