First value empty for options with multiple values in Perl Getopt::Long

Question

could someone help me understanding why the bellow is happening. I am using Perl Getopt::Long to parse options with multiple values, but I am geting some strange results. The following code:

#!/usr/bin/perl
use warnings;
use strict;
use Getopt::Long;

my @b_in = "";
GetOptions( 'b=s{,}'  => \@b_in );
my $blen = @b_in;

print "Length of b args: $blen\n";
print "List of b args: $b_in[0], $b_in[1] and $b_in[2]\n";
print "The first b: $b_in[0]\n";

produces this output:

$ ./optl.pl -b b_abr c_arg
Length of b args: 3
List of b args: , b_abr and c_arg
The first b: 

Why the first argument in the argument list is empty?

Answer 1

Because you initialized it with "" instead of (). The options got appended to the element that was already there.