Reading a file 

my $product_file = 'product-list.txt';

open my $fh, '<', $product_file;

while ( <$fh> ) {
    print;
}

$ ./show-products.pl
PNUM    Description                               Price
752920  Star Wars MiniFig - Baby Yoda             USD 17.95
853610  Minecraft MiniFig Pack                    GBP 19.70
710183  Historical MiniFig - François Mitterrand  EUR 13.25