$TESTHOST = '1.2.3.4';
use IPC::Open2;
$SSH_FLAGS = qq^-t -t -q -o "ConnectTimeout=30"
        -o "PasswordAuthentication=no" -o "StrictHostKeyChecking=no"
        -o "ChallengeResponseAuthentication=no"
        -o "PreferredAuthentications=publickey,server"^;
$SSH_FLAGS =~ s/[\n\r\t]/ /g;
$tmpcmd = "ssh ${SSH_FLAGS} ${TESTHOST} ls";
open2(*SSHREAD, *SSHWRITE, $tmpcmd);
while (<SSHREAD>) {
        $currline = $_; print $currline;
}
close(SSHREAD); close(SSHWRITE);
print "Done!\n";