读取外部 perl 代码作为配置文件的模式

package HWTAG::Config;
# default configurations
my %config_default = (
 category => {},
);

# config file should operate on this variable
our %config;

sub load($$) {
 my ($config_file, $config) = @_;
 %config = %config_default;
 unless (my $return = do $config_file) {
 die "couldn't parse config file: $@" if $@;
 die "couldn't do config file: $!" unless defined $return;
 die "couldn't run config file" unless $return;
 }

# copy instead of reference for multiple instances of objects having
 # different configurations.
 %$config = %config;
}

 $config_file ||= $ENV{HWTAG_CONFIG};
 $config_file ||= catfile($ENV{HOME}, '.hwtag.pl');

HWTAG::Config::load($config_file, $self->{config});