php sftp passwordless automation

Use php security communication library

http://phpseclib.sourceforge.net/

include('Net/SFTP.php');

$sftp = new Net_SFTP('www.domain.tld');
if (!$sftp->login('username', 'password')) {
exit('Login Failed');
}

echo $sftp->pwd() . "\r\n";
$sftp->put('filename.ext', 'hello, world!');
print_r($sftp->nlist());
?>