A tip on your ksh script: uniq -c will do most of what you want:

sort modtype_2430.srt |uniq -c
[download]

In Perl, you can do something similar by sorting the array, then walking through it:

my @sorted = sort @array;
my $last = shift @sorted;
my $count = 1;
foreach my $e (sort @array)
{
  if ($last eq $e)
  {
    $count++;
  }
  else
  {
    print "$count\t$last\n";
    $count=1;
    $last=$e;
  }
}
print "$count\t$last\n";
[download]

Or you can simply use a hash:

my %count;
foreach my $e (@array)
{
  $count{$e}++;
}
while (my($e,$count)=each(%count))
{
  print "$count\t$e\n";
}
[download]

(both of these are untested, but should give you a good general idea).