knoppix@Microknoppix:~$ perl -Mstrict -Mwarnings -E '
> my @lines = (
>    q{1 2 3 4 5 6 7 8 filename 10 11 12 13 14 15 16 17 18},
>    q{1 2 3 4 5 6 7 8 file name 10 11 12 13 14 15 16 17 18},
>    q{1 2 3 4 5 6 7 8 new file name 10 11 12 13 14 15 16 17 18},
>    );
> 
> foreach my $line ( @lines )
> {
>     my @flds = split m{\s+}, $line, 9;
>     @flds    = split m{\s+}, reverse( $flds[ -1 ] ), 10;
>     my $filename = reverse $flds[ -1 ];
>     say qq{>$filename<};
> }'
>filename<
>file name<
>new file name<
knoppix@Microknoppix:~$