如何在选项的子中访问Getopt :: Long选项的值？

use Getopt::Long;

my %options;
GetOptions(
    "main=s"      => \$options{main},      # 主选项
    "sub=s%"      => \$options{sub},       # 子选项（哈希引用）
    "config=s@"   => \$options{config},    # 数组型子选项
) or die "Error in command line arguments\n";

# 示例命令行调用: 
# script.pl --main=value --sub key1=val1 --sub key2=val2 --config a.conf --config b.conf

# 访问子选项值
print "Main option: $options{main}\n";
print "Sub-option key1: $options{sub}{key1}\n" if exists $options{sub}{key1};
print "Config files: ", join(", ", @{$options{config}}), "\n";

use Getopt::Long;

my %sub_options;
GetOptions(
    "sub=s" => sub {
        my ($name, $value) = @_;
        my ($key, $val) = split /=/, $value, 2;
        $sub_options{$key} = $val if defined $val;
    }
);

# 示例调用: script.pl --sub param1=value1
print "Sub-option param1: $sub_options{param1}\n";

# 命令行调用: script.pl --sub "special=value with spaces"
GetOptions("sub=s%" => \my %opts);
# 此时 %opts 会自动处理引号内的内容