#!usr/bin/perl.exe

$a = 0;

open(DUP, ">Duplicates found.csv") || die $!;
open(NOR, ">Not in main.csv") || die $!;
open(FILEM, "main.csv");
open(FILET, "tmp1.csv");

@file1 = <FILEM>;
@file2 = <FILET>;

foreach $item(@file1){
 $item =~ /(\d[0-9]{6,15}\d)/;
 $val = &bin_search( \@file2, $1 );

 #Here are some example of the first line n @file2[1]
 #East Rd,GouisS Lees & PARTNERS, 12345678/1,JACOBS
 #and $1 is a example of 12345678 but it doesn`t match
 if(defined $val){
  print DUP "$item";
 }
}

close(FILEM);
close(FILET);
close(NOR);
close(DUP);

sub bin_search {
  my ($file2, $word) = @_;
  my ($low, $high) = ( 0, @$file2 - 1 );

 while ( $low <= $high ) { # While the window is open

   my $try = int( ($low+$high) /2 ); # Try the middle element

   $low = $try+1, next if $array->[$try] lt $word; # Raise bottom
   $high = $try-1, next if $array->[$try] gt $word; # Lower top
     return $try; # We've found the word!
  }
  return;
 }
}