opendir(DIR, '.') || die "Couldn't opendir: $!\n";

foreach my $filename (reverse((grep /^sniffer/, readdir(DIR)))) 
{
    my $new_name = $filename;    
    if($new_name =~ m/(\d+)/)
    {
    	my $value = $1 +1;    	
    	$new_name =~ s/.*/"sniffer$value\.log"/;      	
    }
    else
    {
    	$new_name =~ s/.*/sniffer1.log/;
    }
    rename($filename, $new_name) unless $filename eq $new_name;    
    close(DIR);