Let's say you have two servers, server1.example.com and server2.example.com, and you want to create a variable on server1, then SSH into server2, create a variable on server2, and be able to use both variables in the SSH session to server2. In this example, variable $a is created on server 1, and has a value of Hello. In the SSH connection to server2, variable $b is created with a value of World. In the SSH connection, both $a and $b are echoed.

#!/usr/bin/perl

use strict;
use warnings;
use Net::SSH::Perl;

my $host = "your_hostname";
my $user = "your_username";
my $pass = "your_password";
my $a = "Hello";

my $ssh = Net::SSH::Perl->new($host);
$ssh->login($user, $pass);
my ($stdout, $stderr, $exit) = $ssh->cmd("b='World'; echo $a \$b;");

print "$stdout\n";

Running the Perl script will print both $a (Hello) and $b (World), which means that the SSH session was able to use both the host $a variable and the local $b variable.

~]# perl example.pl
Hello World