Perl：访问哈希引用中的哈希元素

Question

How would I go about accessing the elements of this hash_ref within a foreach loop?

use strict;
use warnings;

my $services = {
    ftp    => { port => 21,   pr => "",                      waitfor => '/220/'      },
    ssh    => { port => 22,   pr => "",                      waitfor => '/SSH/'      },
    domain => { port => 42,   pr => "",                      waitfor => ''           },
    http   => { port => 80,   pr => "HEAD / HTTP/1.0\n\n",   waitfor => '/200/'      },
    https  => { port => 443,  pr => "HEAD / HTTP/1.0\n\n",   waitfor => '/200/'      },
    pop3    => { port => 110, pr => "",                      waitfor => '/\+OK/'     },
    imap   => { port => 143,  pr => "",                      waitfor => '/OK/'       },
    smtp   => { port => 25,   pr => "",                      waitfor => '/SMTP/'     }
};


foreach my $key (keys %{ $services }) {
    my $port    = $service{port};
    my $waitfor = $services->{$service}->{waitfor};
}

For FTP for instance I want to assign FTP to a scalar and then each key from FTP (port, pr, waitfor) to scalars as well within the foreach loop that cycles between the services (ftp,ssh,dns,etc...)

Thanks for the help in advance.

Answer 1

my $waitfor = $services->{$service}->{waitfor};

should be

my $waitfor = $services->{$key}->{waitfor};

Or you can use something like:

for my $id (keys %$services) {
   my $service = $services->{$id};

   my $port    = $service->{port};
   my $waitfor = $service->{waitfor};
   ...
}

Or even

for my $service (values %$services) {
   my $port    = $service->{port};
   my $waitfor = $service->{waitfor};
   ...
}

Answer 2

you could do this easily..

foreach my $service (keys %$services)   {
print "serivce = $service \n";
foreach my $types (keys %$services->{$service}) {
    print "$services->{$service}->{$types} \n";
}

}