#!/usr/local/bin/perl
 
#Why do you need this?!?
#use Cwd qw(cdir);
use IO::Dir;
use IO::File;
 
print "Please enter the name and location of the directory to parse:\n";
chomp(my $directory = <STDIN>);
 
my $dh = IO::Dir->new($directory)
   || die "Cannot open directory '$directory': $!\n";
 
my @filenames;
push @filenames, $_ for map { "$directory/$_" } grep !/^\.\.?/, $dh->read;
 
$dh->close;
 
my %file_data;
foreach my $filename (@filenames)
{
   my @final_data;
 
   # Why do you need to do this?!?
   #chdir "./data";
 
   my $fh = IO::File->new($file)
      || die "Cannot open file '$file': $!\n";
 
   my $i = 0;
   while (<$fh>)
   {
      next while $i++ <= 14;
 
      push @{$file_data{$file}}, (split /\t/)[3];
   }
   $fh->close;
}
 
# Now, at this point, you have a hash called %file_data
# which is keyed by filename. Each filename points to an
# array reference contained the values in the 4th column,
# starting at the 15th line. What do you want to do with it?