Use Net::Telnet

From the doc:

        use Net::Telnet ();
        $t = new Net::Telnet (Timeout => 10,
                              Prompt => '/bash\$ $/');
        $t->open("sms.server.inter.net");
        $t->login($username, $passwd);
        @lines = $t->cmd("sms.pl-msg=$opt{msg} -num=123456789");
        print @lines;
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Bye!