title: Call to undefined function ssh2_connect()
body: <pre><code>$connection = ssh2_connect($SFTP_SERVER, 22);
  ssh2_auth_password($connection,$SFTP_USERNAME,$SFTP_PASSWORD);
  $sftp = ssh2_sftp($connection);
  </code></pre>
  
  <blockquote>
    <p>Fatal error: Call to undefined function ssh2_connect() in /var/www/html/beta/0sftp.php on line 33</p>
  </blockquote>
  
  <p>my system is CentOS 6.4 all the required extensions is installed but I don't know how to verify.</p>