#!/usr/bin/perl

# http://perlmonks.org/?node_id=1178340

use strict;
use warnings;

while(<DATA>)
  {
  print /^(?!.*_\d)/ ? "    matched $_" : "not matched $_";
  }

__DATA__
aa1.2
aa1_bb2
aa1_2
aa1_2bb
1aa

##</code><code>##

/^(?!.*[-_]\d)/