#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my $input = <DATA>;
my @data = split /\s+/, $input;

my $last_display;
my %results;
for my $datum (@data) {
    my ($key, $value) = split /=/, $datum, 2;

    if ($key eq 'displaynum') {
        $last_display = $value;
    }

    if ($key eq 'value') {
        push @{$results{$last_display}}, $value;
    }
}

print Dumper \%results;

for my $key (keys %results) {
    print join "\t", $key, @{$results{$key}}, "\n";
}



__DATA__
displaynum=00 value=Some0 displaynum=01 value=Some1 displaynum=02 value=Some2 value=Some3


__END__
$VAR1 = {
          '01' => [
                    'Some1'
                  ],
          '00' => [
                    'Some0'
                  ],
          '02' => [
                    'Some2',
                    'Some3'
                  ]
        };
01	Some1	
00	Some0	
02	Some2	Some3