use File::Find::Rule qw/ find rule /;
my $gonerDirs = rule(
 directory => name => [ 'baby', 'dead' ],
 qw/ prune discard/,
);

## use File::Find::Rule::Permissions (); ## ??? not for win32
## my $keeperFiles = rule( file => permissions => [ '???' ],... );

my $keeperFiles = rule( file => exec => \&worldWriteable ... );
my @files  = find(
    not => $gonerDirs  ,
    any => $keeperFiles ,
    in => \@startdirs,
);