#!/usr/bin/perl
use Expect;
use strict;
use warnings;
use Data::Dumper;

sub loop {
    
    my $command = shift;
    my $debug = 0;
    my $timeout = 2;
    my $username = "username";
    my $password = "password";

    # create an Expect object by spawning another process
    my $exp = Expect->spawn($command)
    or die "Cannot spawn $command: $!\n";

    my $login = Expect->init($exp);
    $login->raw_pty(1);
    $debug and $login->log_user(1);

    $debug and print "waiting for password prompt\n";
    $login->expect($timeout, ':')
    or die "expect failed\n";
    $debug and  print "prompt seen\n";

    $login->send("$password\n");
    $debug and print "password sent\n";

    $login->expect($timeout, "\n")
    or die "bad password\n";
    $debug and print "password ok\n";

    my $send;

    while(<$login>) {
    # removing trailing characters such as \n
    chomp $_;
    # removing blank space before and after the string
    $_ =~ s/^\s+|\s+$//g;
    print "\$_: ".$_."\n";
    $send = $_;
    }

    # if no longer needed, do a soft_close to nicely shut down the com
+mand
    $login->soft_close();

    return $send;

}

my @commands = ( "sudo -k; sudo service ntp stop" , 
         "sudo -k; sudo ntpd -gq" , 
         "sudo -k; sudo service ntp start" );

my @final = ();

foreach my $input (@commands) {

    my @output = loop($input);

    push(@final,@output);
    
}

print Dumper(\@final);

__END__

$_: * Stopping NTP server ntpd                                        
+   [ OK ] 
$_: ntpd: time slew +0.106441s
$_: * Starting NTP server ntpd                                        
+   [ OK ] 
$VAR1 = [
          '* Stopping NTP server ntpd                                 
+   [ OK ]',
          'ntpd: time slew +0.106441s',
          '* Starting NTP server ntpd                                 
+   [ OK ]'
        ];
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