I'm new to programming. I have written a perl script which does the following. 1) ssh into a remote machine 2) execute a sequence of commands. The script requires user interaction in between.It needs user name and password. I'm not sure how to proceed with that.

use Net::SSH::Expect;
use strict; 
use warnings;

#login to a remote host
my $ssh = Net::SSH::Expect->new (host => "ipaddr",
                             password=> 'pwd',
                             user => 'username',
                             raw_pty => 1);


my $login_output = $ssh->login();
[download]

The login is successful. Now, for the below scp command i'm prompted to enter the username and password of that system. Enter usename for remote scp server: Enter the password for the remote server: The script stops here. This is what i tried.but no luck

my $cpscp = $ssh->exec("copy scp install ip addr  filename");

my $usr = $ssh->waitfor ("Enter usename for remote scp server:\s*\z ",
+ 5);
if ($usr) 
{
print("string found \n");
my $pwd =$ssh->send("root");
} 
else 
{
print("No string found\n");
}
[download]

The script is unable to identify it. "no string found" I also tried the following

$ssh->waitfor('Enter username for remote scp server:\s*\z ', 5) or die
+ "not found";
$ssh->send("root");
[download]