List last 100 registered WordPress / BuddyPress users without a gravatar or uploaded avatar

gistfile1.phtml

/**
 * 
 *	List last 100 registered users without a gravatar or uploaded avatar
 *
 */
add_action( 'admin_menu', 'wk_list_members_without_profile_picture' );
function wk_list_members_without_profile_picture(){
	add_menu_page( 'Members w/o picture', 'Members w/o picture', 'manage_options', 'wb-without-avatar', 'wb_without_avatar' ); 
}


function wb_without_avatar(){
	
	echo '<h1>Last 100 registered users without a profile picture</h1>';
	$args = array(		
		'orderby'      => 'registered',
		'order'        => 'DESC',
		'number'       => '100',
	 );
	$users = get_users( $args );

	// we'll create a list of comma separated emails as well
	$email_list = array();

	echo '<table>';

	foreach ($users as $user) {
		
		if ( wb_has_avatar($user->ID)) continue;
		if ( wb_has_gravatar($user->user_email)) continue;

		// if there's no avatar and no gravatar create a row with email, date of registration and link to profile page
		echo '<tr>';
		printf('<td>%s</td>', $user->user_email);
		printf('<td>%s</td>', $user->user_registered);
		printf('<td><a href="%s">profilo (%s)</a></td>', get_admin_url().'user-edit.php?user_id='.$user->ID ,$user->ID);
		echo '</tr>';

		$emails_bcc[] = $user->user_email;

	}
	echo '</table>';

	echo '<h2>Email friendly format</h2>';
	foreach ($emails_bcc as $email) printf('%s;<br>', $email);

}

// returns true if the uploaded avatar is different than the default one
function wb_has_avatar( $user_id ) {
    $retval = false;

    if ( bp_core_fetch_avatar( array( 'item_id' => $user_id, 'no_grav' => true, 'html' => false ) ) != bp_core_avatar_default( 'local' ) )
        $retval = true;

    return $retval;
}


// returns true if there's a gravatar associated with this email
function wk_has_gravatar( $user_email ) {

	$hashkey = md5(strtolower(trim($email)));
	$uri = 'http://www.gravatar.com/avatar/' . $hashkey . '?d=404';

	$data = wp_cache_get($hashkey);
	if (false === $data) {

		$response = wp_remote_head($uri);
		if( is_wp_error($response) ) $data = 'not200';
		else $data = $response['response']['code'];

		// cache the response
	    wp_cache_set($hashkey, $data, $group = '', $expire = 60*5);

	}		
	if ($data == '200') return true;
	else return false;
}