I just want to add why you are printing the value of '1', other monks have already pointed out a fix to your problem.

Your code, print length(@attrvals); is equivalent to print length( scalar @attrvals );, which is equivalent to print length("2"), which prints "1", the length of string "2".

Run the demo code below -

my @array = 0..99;  # 100 element array
print length(@array);
[download]

The output is 3, since the string "100" (elements) has 3 characters.