Count the capture groups in a qr regex?

Question

I am working on a project which at one point gets a list of files from an ftp server. At that point it either returns an arrayref of files OR if an optional regex reference

Answer 1

You could use something like:

sub capturing_groups{
    my $re = shift;
    "" =~ /|$re/;
    return $#+;
}

say capturing_groups qr/fo(.)b(..)/;

Output:

2