my $line = 4;

while (@lines > 3) {
    
    # check first 3 lines against the 4th line
    my @vals = split /\s+/, $lines[3];
    my @chk = split /\s+/, join(' ', @lines[0..2]);
    my %match;
    foreach my $val (@vals) {
        $match{$val}++ if grep { $val eq $_ } @chk;
    }
    my @match = sort keys %match;
    my @nomatch = grep { not exists $match{$_} } @vals;

    my $match = @match;
    my $nomatch = @nomatch;
   
# do whatever you want with the matches and no-matches    
    print MATCH "$line: \tmatch = @match\n";
    print NOMATCH "$line: \tnomatch = @nomatch\n";
    
    
    
    $line++;

    # get rid of first line so next loop will be 2-6 and so on
    shift @lines;
}
[download]

Here's my guess at something like what you want. Instead of printing @match and @nomatch at the end, just write their contents to the proper files, and change the input to read from your input file.

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11109150
use warnings;

my $x = 9;

my %uniques;
my @match;
my @nomatch;

while( <DATA> )
  {
  print;
  for my $element ( split )
    {
    if( keys %uniques < $x )
      {
      $uniques{ $element }++;
      }
    else
      {
      if( $uniques{ $element } )
        {
        push @match, $element;
        }
      else
        {
        push @nomatch, $element;
        }
      }
    }
  }

print "\nMATCH:\n@match\n\nNOMATCH:\n@nomatch\n";

__DATA__
1 2 6 4 5
6 7 8 9 10
1 2 11 12 13
6 14 15 16 17
[download]

Outputs:

1 2 6 4 5
6 7 8 9 10
1 2 11 12 13
6 14 15 16 17

MATCH:
1 2 6

NOMATCH:
11 12 13 14 15 16 17
[download]

Hi Scotmonk,

This is a great use-case for using an ordered hash (like a hash but with key insertion order preserved). Fortunately, such a module exists. For this demonstration, I'm more interested in the hash keys, not the hash values (i.e. hash key-driven implementation).

# https://www.perlmonks.org/?node_id=11109163

use strict;
use warnings;
use feature 'say';

use Hash::Ordered;

tie my %elems, 'Hash::Ordered';
tie my %match, 'Hash::Ordered';
tie my %nomatch, 'Hash::Ordered';

my $skip_duplicates = 0;  # set to 1 to skip duplicates
my $num_elements = 13;    # number of elements to read
my $num_read = 0;         # number of elements read

my @lines = <DATA>;
chomp @lines;

# read elements

while ( @lines && $num_read < $num_elements ) {
    my $line = shift @lines;
    foreach my $elem ( split / /, $line ) {
        if ( $skip_duplicates ) {
            $num_read++ unless exists $elems{ $elem };
        } else {
            $num_read++;
        }
        $elems{ $elem } = undef;
        last if $num_read == $num_elements;
    }
}

say "data elements";
say join(' ', keys %elems);

# matched, not matched

if ( @lines ) {
    foreach my $elem ( split / /, shift @lines ) {
        ( exists $elems{ $elem } )
            ? $match{ $elem } = undef
            : $nomatch{ $elem } = undef;
    }
    say "match";
    say join(' ', keys %match);
    say "nomatch";
    say join(' ', keys %nomatch);
}
else {
    say "no more lines";
}

__DATA__
1 2 6 4 5
6 7 8 9 10
1 2 11 12 13
6 14 15 16 17
2 18 19 20 21
[download]

Output: $skip_duplicates = 0

data elements
1 2 6 4 5 7 8 9 10 11
match
6
nomatch
14 15 16 17
[download]

Output: $skip_duplicates = 1

data elements
1 2 6 4 5 7 8 9 10 11 12 13 14
match
2
nomatch
18 19 20 21
[download]

Regards, Mario

Thankyou Mario

I get an error on execution
Can't locate Hash/Ordered.pm in @INC (@INC contains: C:/Dwimperl/perl/site/lib C:/Dwimperl/perl/vendor/lib C:/Dwimperl/perl/lib .) at compare001.pl line 7.

How can I remedy this ?
Thankyou
Michael

I successfully installed Hash::Ordered
still gettng this message. Is there something else I should do ?
Can't locate Hash/Ordered.pm in @INC (@INC contains: C:/Dwimperl/perl/site/lib C:/Dwimperl/perl/vendor/lib C:/Dwimperl/perl/lib .) at compare001.pl line 8. BEGIN failed--compilation aborted at compare001.pl line 8.