my @files_list = glob "$inpath/filename*.txt";
foreach my $var (files_list){
   my @array[i]=$var;
 i=i+1;
}
my @sorted_list = reverse sort @myarray; #@myarray  contains the files
foreach my $file (@sorted_list){
	my $single_file = glob "$path/$file*.txt"; 


    	some stuff on files......................

}