I am still trying to understand how to put system and have header in the right place. Ideally what I am trying to achieve is this :

============hostname01============

bla bla bla

============hostname02============

bla bla bla 

============hostname03============

bla bla bla
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#!/usr/bin/perl -w

use warnings;
use strict;
use Expect;

my $filename = "/var/tmp/expect_script.log";

my $header = "\n\n======= system =======\n";
my $timeout = 60;

my @servers = qw(
   hostname01
   hostname02
   hostname03
   hostname04

);


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);

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

 );
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