foreach (@getcert) {
  $c = $_;

##</code><code>##

foreach my $c (@getcert) {

##</code><code>##

use List::MoreUtils qw( mesh );
my @users = qw( alice bob charlie );
my @ids   = qw( 123 456 789 );
my %id_of = mesh @users, @ids;
# now $id_of{ 'alice' } == 123

##</code><code>##

sub mesh (\@\@;\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@\@) {
    my $max = -1;
    $max < $#$_  &&  ($max = $#$_)  for @_;

    map { my $ix = $_; map $_->[$ix], @_; } 0..$max; 
}