What steps have you undertaken to ascertain your assumption?

For example, the following prints the number of elements in the array @columns:

print 0+@columns;
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And the following shows you the values of the elements:

use Data::Dumper;
print Dumper \@columns;
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Personally, I would always look at the line where @columns gets initialized, and also inspect the source data, by printing the line $line1.