#!/usr/bin/perl -w 

use warnings;
use strict;
use Expect;

my $filename = "/var/tmp/expect_script.log";
my $header = "\r\n\r\n======= system =======\r\n";
my $timeout = 60;  
my $my_header = $header

my @servers = qw(
     remotehost
     
);


for my $server (@servers) {
# do your thing with $server

    change_password($server);

 }

sub change_password {
      
      my $system = shift;
      my $ssh = Expect->new('ssh amagana@' . $system);

$ssh->debug(1);
$ssh->log_file("$filename");
$my_header =~ s/system/$system/;
$ssh->print_log_file($header);
$ssh->expect ( $timeout, 
      [ qr/Password:/],
      [ qr/Are you sure you want to continue connecting \(yes\/no\)?/]

 );

if ($ssh->match() =~ m/Are you sure you want to continue connecting \(yes\/no\)?/ ) { 
$ssh->send("yes\r");
}

elsif ($ssh->match() =~ m/Password:/ ) {

$ssh->send("mycurrentpassword\n");

}

$ssh->expect(60, '$');
$ssh->send("su - root\n");
$ssh->expect(60, 'Password:');
$ssh->send("rootpassword\n");
$ssh->expect(60, '#');
$ssh->send("hostname\n");
$ssh->expect(60, '#');
$ssh->send("uptime\n");
$ssh->expect(60, '#');
$ssh->send("passwd amagana\n");
$ssh->expect(60, 'New Password:');
$ssh->send("mynewpassword\n");
$ssh->expect(60, 'Re-enter new Password:'); 
$ssh->send("mynewpassword\n");
$ssh->expect(60, '#');
$ssh->send("exit\n");
$ssh->expect(60, '$');
$ssh->send("exit\n");
$ssh->close();
}