Get Attached Images from Post on Wordpress

gistfile1.txt

    <?php function postimage($size=thumbnail, $qty=-1) {
    if ( $images = get_children(array(
    'post_parent' => get_the_ID(),
    'post_type' => 'attachment',
    'numberposts' => $qty,
    'post_mime_type' => 'image',)))
    {
    foreach( $images as $image ) {
    $attachmenturl=wp_get_attachment_url($image->ID);
    $attachmentimage=wp_get_attachment_image( $image->ID, $size );
     
    echo '<meta property="og:image" content="'.$attachmentimage.'"/>';
    }
    } else {
    echo "No Image";
    }
    } ?>