my $dir = 'test2';
opendir(DIR,$dir) or die $!;

while($datei = readdir(DIR))
{
	$path = $dir . '/' . $datei;
	#print "\n$path\n";
	next unless -f $path;
	@entries;
	{
		$measure;
		local $/ = "\nDUT No\n";
		open $fh, '<', $path or die $!;
		while($entry = <$fh> )
		{
			chomp $entry;
			@mms = $entry =~ /Measurement:\s*([\d.]+)/;
			$measure = $mms[0] unless defined $measure;
			if(grep{ $_ == $measure }@mms)
			{
				$entry = "DUT No\n". $entry unless $entry =~ /^DUT No/;
				push @entries, $entry;
			}
		}
	}
	open OUTPUT, '>',$path;
	print OUTPUT $_,"\n" for @entries;
	#print $datei;
	close OUTPUT;
}