use strict;

#open(IN, '<', "test.in") || die "\nCan't open test.in\n $!\n";
my @values;
while(<DATA>) {
	if(/<ref id="(.*?)">/){
           push @values ,$1;
           next;
    }
	if(m|</end>|){
        print "New Group: @values \n";
        @values=(); # Empty it
    }
}
#close(IN);
__DATA__
<ref id="ref1">
<ref id="ref2">
<ref id="ref3">
</end>
<ref id="ref4">
<ref id="ref5">
</end>
<ref id="ref6">
<ref id="ref7">
<ref id="ref8">
</end>