不推荐使用Hash作为引用- Perl

Question

我正在尝试在我的windows平台上安装scmbug。在下面的方法中，我将Hash作为引用错误。请参阅"HERE“注释以查看它发生的位置。

我应该用$mail替换所有的%mail吗？

我试过了，但得到了其他错误。说

全局符号"$mail“需要显式的包名

如何解决这个问题？

sub mail_notification_send_mail {
   my $self = shift;
   my ($request, $subject, $message, $mailing_list) = ( @_ );
   my %mail;

   # Set values. This permits users to override the default behavior
   # of Mail::Sendmail
   %mail = \%{ $request->{ policies }->{ mail_notification }->{ mail_settings } };
   %mail->{ 'X-Mailer' } = "Mail::Sendmail version $Mail::Sendmail::VERSION";  HERE
   %mail->{ Subject } = $subject; HERE
   %mail->{ Message } = $message; HERE

   #
   # Since we just reset %mail to values, we haven't really picked up
   # the To,From,Reply-To that were computed. We do this next
   #

   # Don't blindly ignore the To list that was computed
   my $mailing_list_to = $self->emails_to_csv( $mailing_list->{ To } );
   %mail->{ To } = $mailing_list_to; HERE

   # Don't blindly ignore the From list that was computed
   my $mailing_list_from = $self->emails_to_csv( $mailing_list->{ From } );
   %mail->{ From } = $mailing_list_from; HERE

   # Don't blindly ignore the 'Reply-To' list that was computed
   my $mailing_list_replyto = $self->emails_to_csv( $mailing_list->{ 'Reply-To' } );
   %mail->{ 'Reply-To' } = $mailing_list_replyto; HERE


   if ( !sendmail(%mail) ) {
   my $msg = "Sending mail on " . $request->{ name } .
       " failed. Log error was:\n" . $Mail::Sendmail::error . "\n";
   $request->add_result(1, $msg);
   }
}

谢谢

Answer 1

文档：perldoc perlref

您有一个hashref，但您正在使用一个hash的符号。将所有%mail替换为$mail。

您必须：

%mail = \%{ $request->{ policies }->{ mail_notification }->{ mail_settings } };

\%告诉perl解除对散列的引用并返回一个散列引用，但是您将其分配给一个散列。我敢打赌你也会收到警告的。这一行应该是：

$mail = $request->{ policies }->{ mail_notification }->{ mail_settings }; ## change all `%mail` to `$mail`

或

%mail = %{ $request->{ policies }->{ mail_notification }->{ mail_settings } }; ## change all `%mail->{something}` to `$mail{something}`. 

Answer 2

使用$mail->{ ... }来解除引用。但在本例中，您使用的是散列%mail而不是引用，因此访问其成员的正确方法是不使用取消引用操作符->。一个简单的$mail{...}就足够了。