use strict;
use warnings;

my @filesThisRun = (qw{file1 file2 ... fileN);
my %fileInfo = ();

foreach my $file (@filesThisRun)
{
    open my $lookupFH, q{<}, $file
       or die qq{open: $file: $!\n};

    while (<$lookupFH>)
    {
        my ($refName, $refID) = (split m{\t})[3, 4];
        $fileInfo{$file} = {$refID => $refName};
    }

    close $lookupFH
       or die qq{close: $file: $!\n};
}