I'm glad you are making progress. :)

> I didn't get where I missed "sigil $ in line once". 

$hash{line}=1;  
# should be
$hash{$line}=1;
[download]

> Use of uninitialized value in line 34 

You probably parse empty lines resulting in undefined variables.

Skip them with next , compare Re: Filtering Output from two files

>  after the loop 

The print belongs inside the loop.

please use code tags and indentation in your next post.