#! /usr/bin/perl
# vim:ts=4 sw=4 sts=4 et nu fdc=3:
use strict;
use warnings;

use Data::Dumper;
$Data::Dumper::Sortkeys = 1;

# data structure: Hash of Arrays
# Device => [ list of vlan IDs ]
my %vlan = (
    device_1 => [ 1..38 ],
    device_2 => [ 1..48 ],
    device_3 => [ 1..24 ],
);

# take 10 items of each device sub hash
# process items
# redo until all sub hashs are empty

my %data;
do {
    %data = ();

    for my $dev ( keys %vlan ) {
        
        # skip if no vlan IDs left for current device
        next if 0 == @{ $vlan{$dev} };

        # extract next 10 IDs of current device
        $data{$dev} = [ splice( @{$vlan{$dev}}, 0, 10 ) ];
    }

    # process extracted data
    print Dumper( \%data );
}
while ( keys %data );

__END__