use File::Find;	
my $ext = "dat";
my $nom = 0;

find ( \&ripper, @ARGV) ;

sub ripper { ## First implementation
unless(s/\.$ext$//i) {return;}
my $file = $_;  #using $_  screws up grep
$nom += unlink(grep(/\Q$wang\E\.(?!$ext)/, glob("*")),"\n"); 
}

sub ripper2 { ## Second implementation
my $file = $_;
return unless(s/\.(?!$ext)$//i); 
my $priority = $_ . $ext;
if(-e $priority && !-d $priority) { $nom += unlink $file; }
}