I think your problem is that you do too much at once without testing the result from the intermediate steps.

Most of my scripts start with

# always use those:
use strict;
use warnings;

use Data::Dumper;
[download]

When you suspect that split isn't working the way you think it is, try adding the line print Dumper \@foo; immediately after the split, and look if the results are what you execpted it to be.

The $foo[$_] is always empty so

for iterates over the values in the array, not the indexes. So instead of $foo[$_] just write $_.