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

$/ = 'authDataAlias=';

my %no_dupes;

foreach my $line (<DATA>)
{

     if ($line =~ m/^"(.*?_DM\S+)"/i)
        {
        $no_dupes{$1} = 0;
        }
}

print "$_\n" for keys %no_dupes;

__DATA__
<factories xmi:type="resources.jdbc:CMPConnectorFactory" xmi:id="CMPConnectorFactory_1195273978412" name="dataSource" authMechanismPreference="BASIC_PASSWORD" authDataAlias="cell-tstc-65_DM/userQ" connectionDefinition="ConnectionDefinition_1054132487569" cmpDatasource="DataSource_1195273954323"><factories xmi:type="resources.jdbc:CMPConnectorFactory" xmi:id="CMPConnectorFactory_1195273978412" name="dataSource" authMechanismPreference="BASIC_PASSWORD" authDataAlias="cell-tstc-65_DM/userQ" connectionDefinition="ConnectionDefinition_1054132487569" cmpDatasource="DataSource_1195273954323"><factories xmi:type="resources.jdbc:CMPConnectorFactory" xmi:id="CMPConnectorFactory_1195273978412" name="dataSource" authMechanismPreference="BASIC_PASSWORD" authDataAlias="cell-tstc-65_DM/userF" connectionDefinition="ConnectionDefinition_1054132487569" cmpDatasource="DataSource_1195273954323">
<factories xmi:type="resources.jdbc:CMPConnectorFactory" xmi:id="CMPConnectorFactory_1195273978412" name="dataSource" authMechanismPreference="BASIC_PASSWORD" authDataAlias="node-tstc-65_DM/userF" connectionDefinition="ConnectionDefinition_1054132487569" cmpDatasource="DataSource_1195273954323">