my $ssh2 = Net::SSH2->new();
$ssh2->debug(1);
......
.....
$chan2->close;

my $chan3 = $ssh2->channel();
if( $ssh2->auth_ok ){ print "auth ok"}
     else{  print "auth lost\n" }

$chan3->blocking(0);  # try to set blocking 0
$chan3->shell();