use warnings;
use strict;

while ( defined( my $line = <DATA> ) ) {
    chomp $line;
    print $line, $/ if  $line =~ m/\-[0-9a-z]{3}/;
}

__DATA__
 DOC_001_123

DOC_002_214

DOC_001-548

DOC_001-987 

##</code><code>##

DOC_001-548
DOC_001-987 

##</code><code>##

use re 'debug';