How do I accept an output parameter array and a scalar in perl?

Question

I have a function where I want to check if a path exists, and if it does, add that to an array. Here's what I tried:

# If a path exists, adds the canonical version of that path to an array
sub AddPathCandidate {
    my (@$target, $path) = $_;
    die ('path needed') unless defined($path);
    $path = File::Spec->canonpath($path);
    if (-e $path) {
        push(@{$target}, $path);
    }
}

where the caller looks like:

my @exampleDirs = ();
AddPathCandidate(\@exampleDirs, $inDir . 'a');
AddPathCandidate(\@exampleDirs, $inDir . "../b/a/$arch");
AddPathCandidate(\@exampleDirs, $inDir . "../../b/a/$arch");

But the "die" statement always executes; the second parameter of AddPathCandidate isn't getting through somehow.

Is what I'm trying to do here even possible or is there some more "perl-ish way" to accomplish this?

Answer 1

Declare the variable as $target when unpacking your arguments, and unpack from @_ :

my ($target, $path) = @_;
    ^                 ^^