An anonymous subroutine would work here: 
my $cond = sub { !-d $_[0] };
perform_check($cond);

sub perform_check {
  my $cond = shift;
  ...
  if ($cond->($possible_directory)) {
    doSomethingElse();
  }
}

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In reply to Re: Pass conditions to a subroutine by pc88mxer
in thread Pass conditions to a subroutine by PerlRob

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