【Perl 】初心者コーナーPart5

ああ、昼寝してた。すまん。

#!/usr/bin/perl -w

use constant NOT_EXISTS => 0;
use constant EXISTS => 1;
use constant LAST_MODIFIED => 3;

@old = map{ [ split ] } <OLD>;

while($rec = <NEW>){
    chomp $rec;
    $is_exists = NOT_EXISTS;
    @new = split(/\s+/,$rec);
    
    foreach $old (@old){
        if(($new[0] eq $old->[0]) && ($new[1] eq $old->[1]) && ($new[2] eq $old->[2])){
            $is_exists = EXISTS;
            if($new[LAST_MODIFIED] ne $old->[LAST_MODIFIED]){
                print $rec , "\n";
                last;
            }
        }
    }
    if($is_exists == NOT_EXISTS){
        print $rec , "---unmatched\n";
    }
}

やりたいのはこういったこと？