Your last piece of code does not work - You are attempting to de-reference $flag, which yields undef, and prints zero.

This ugly code below does work:

#use strict;
use Readonly;

my @EXPORTS=qw(DBG_ONE DBG_TWO  DBG_FOUR);

Readonly::Scalar my $DBG_ONE  => 1;
Readonly::Scalar my $DBG_TWO  => 2;
Readonly::Scalar my $DBG_FOUR => 4;

foreach my $flag (@EXPORTS) {
  printf "flag = %s, value = 0x%04x\n", $flag, eval( "\$" . $flag );
}
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but I hate evals, and you would be much better served by using something like

 Readonly::Hash    my %DBG_Val => (DBG_ONE => 1, DBG_TWO => 2, DBG_FOU
+R =>4);
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Update:bruceb3's code works fine. Ignore the code I posted, which is essentially identical to bruceb3's but uses eval (and thus avoids conflict with "use strict 'refs'). Do follow the advice regarding using a Readonly HASH - much safer, and probably closer to what you need to do.