barcodes.pl

use Modern::Perl;
use Koha::Biblios;
use Koha::Items;

my $biblios = Koha::Biblios->search;
my $branchcode='ppa';
while (my $biblio=$biblios->next) {

    Koha::Item->new(
        {
            biblionumber  => $biblio->biblionumber,
            homebranch    => $branchcode,
            holdingbranch => $branchcode,
            barcode       => 'barcode_'.$biblio->biblionumber,
            itype         => $biblio->biblioitem->itemtype
        }
    )->store;

}