At first glance this seemed unnecessarily complicated but then I thought, "No, it couldn't be doing that!" So I tried... 
#!/usr/bin/perl
use Modern::Perl;

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<};
    }

foreach my $line ( @lines ) {
    my  @flds     = split(' ', $line);
    my  $filename =  join(' ', @flds[8 .. $#flds - 9]);
    say qq{<$filename>};
    }

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Yes, yours preserves multiple spaces in the file name. Thanks for the enlightenment JohnGG!

In reply to Re^2: parse a line with varied number of fields by vt220
in thread parse a line with varied number of fields by raggmopp

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