However, the preprocess returns everything,

That is kinda what you tell it to do. elsif (-d && /advanced/ ) {push (@toreturn, $_);} means "hey, I've found one I want to ignore, but I choose to NOT ignore , aren't I funny?"

so I need to use the preprocess possibility

Not exactly :)

use File::Find::Rule

use File::Find::Rule;
my $rule = File::Find::Rule->new;
$rule->or(
## first rule, things to ignore, to skip
    $rule->new
        ->directory
        ->name('CVS', qr/advanced/i )
        ->prune
        ->discard,
    $rule->new
        ->file
        ->name('*.log')
);
my @files = $rule->in( @startdirs );
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or use Path::Class::Rule , it doesn't use File::Find underneath, and actually names the prune/discard option skip, and provides a real iterator , its brilliant

use Path::Class::Rule;
my $rule = Path::Class::Rule->new;
$rule->skip(
    $rule->new->dir->name(qr/advanced/i),
    $rule->new->skip_vcs
);
$rule->file->name('*.log');
# iterator interface
my $next = $rule->iter( @dirs );
while ( my $file = $next->() ) {
    ...
}
[download]