Re^3: Reading file and matching lines

[kcott]

Firstly, you have no duplicates in any (of what you're calling) "scope". G123465798 is not a duplicate of G123456798: you've transposed the 5 and the 6. I've fixed this in the example below.

There's a standard idiom for checking for duplicates in this sort of scenario. Use a hash (often called %seen) that has as its keys whatever identifier you're checking. While processing, if the key exists, it's a duplicate, so skip/flag/etc. as appropriate; if the key doesn't exist, it's unique, so use it and then add it to the hash (usually done with a postfix increment).

Here's an example using your fixed data:

#!/usr/bin/env perl -l

use strict;
use warnings;

my @data = (
    [ qw{E123456789 G123456798 h12345} ],
    [ qw{E1234567 E7899874 G123456798 G123456789 G123456798 h1245} ],
);

for my $scope (@data) {
    my %seen;

    for my $identifier (@$scope) {
        print $identifier unless $seen{$identifier}++;
    }
}

Output:

E123456789
G123456798
h12345
E1234567
E7899874
G123456798
G123456789
h1245