#! /usr/bin/perl

use strict;
use warnings;
use Data::Dumper;

# State machine
use constant CODE  => 'CODE';
use constant EVENT => 'EVENT';

# Codes pre-parsed from file1
my %codes = (
    12131 => 1,
    34234 => 1,
    53435 => 1,
    46566 => 1,
    34522 => 1,
);

my %results;
my ($code_id, $event_id);

my $state    = 'CODE';
my $re_code  = qr{Code \s+ id \s+ -(\d+)- }x;
my $re_event = qr{Event \s+ id \s+ (-\d+-) }x;

LINE:
while( <DATA> ) {

    chomp();

    if( ($state eq CODE) && /$re_code/ ) {
        # Check that code is valid
        if( $codes{$1} ) {
            $code_id = $1;            
            $state   = EVENT;
        } else {            
            next LINE;
        }
    } else {
        if( ($state eq EVENT) && /$re_event/ ) {
            $results{$code_id} = $1;
            $state = CODE;
        } else {            
            next LINE;
        }        
    }
}

print Dumper(\%results);

1;

__DATA__
some content
some content
some content
some content
some content
blah. blah.
Code id -46566-
some content
some content
some content
some content
Event id -445778441211-
some content
some content
some content
some content
some content
some content
some content
Code id -12131-
some content
some content
some content
some content
some content
some content
some content
some content
some content
Event id -123443111131-
Code id -12342-
some content
some content
some content
some content
some content
some content
some content
some content
Event id -445987432141-