Re: 
GetOptions (
  "a=s" => \@a,
  "b=s" => \@b
);
@a = split(/,/,join(',',@a));
@b = split(/,/,join(',',@b));

[download]

You don't have to parse after the fact; you can have the reference in the GetOptions() call be a sub ref and mangle things there. E.G. 

my $opt = { # this has to be first because the sub-refs
            # below are closures using it.
  grot => [],
};
my $splitter = sub {
    my ($name, $val) = @_;
    push @{$opt->{$name}}, split q{,}, $val;
};
GetOptions( $opt,
  'grot=s@' => $splitter,
) or die "can't parse options";

[download]

It's not so much useful in this case, where there is only one use, but if you have several options which can have multiple comma-separated values, this piece of code can be handy. I've also used other sub-refs in GetOptions, e.g. if the option value specifies a file-name, but you want the option to end up containing the file contents, you might use something like: 

my $from_file = sub {
    my ($name, $val) = @_;
    open my $fh, "<$val" or die "can\'t open file \'$val\'";
    local $/ = undef;
    $opt->{$name} = <$fh>;
    close($fh);
};

[download]

In reply to Re^2: GetOpts::long Multiple Parameters per option by thargas
in thread GetOpts::long Multiple Parameters per option by PyrexKidd

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