#!/usr/bin/perl

use strict;

my %count;
my $directory = "c:\\Test";

opendir( DIR, $directory )
  || die "Unable to open directory - $!\n";
my @files = grep /\.txt/, readdir( DIR );
closedir( DIR );

open( OUTFILE, ">> $directory\\COID_LIST.txt" )
  || die "Unable to open write file! - $!\n";

foreach my $file (@files) {
    open( FH, "$directory\\$file" )
      || die "Unable to open $file - $!\n";
    while( <FH> ) {
        my $ID = substr( $_, 260, 5 );
        print OUTFILE "$ID\n";
        $count{$ID}++ if ( defined( $ID ) );
    }
    close( FH );
}

print "Number of company ID = " . scalar keys %count;