#!/usr/bin/perl
use strict;
use warnings;
use autodie;

#system ('grep -l "DATAmessage.*3\.0" *.xml > 3.0_files_arraydata.txt'); 

open my $OUT, '>', '3.0_files_arraydata.txt';
foreach my $filename (<*.xml>)
{
    open my $in, '<', $filename;
    print $OUT "$filename\n" if grep{/DATAmessage.*3\.0/}<$in>;
}