function update_my_metadata() {
    $args = array(
        'post_type' => 'movies', // Only get the posts
        'post_status' => 'publish', // Only the posts that are published
       // 'posts_per_page'   => -1 // Get every post
	    'post__in' => array(56,57)
    );
    $posts = get_posts($args);
    foreach ($posts as $post ) {
        // Run a loop and update every meta data
		$key_name = get_post_meta($post->ID, 'field_imdbid', true);
		$api = file_get_contents('http://www.omdbapi.com/?i='.$key_name.'&apikey=e2ade02b');
		$json = json_decode($api, true);
		$getImdbRating = $json['imdbRating'];
		$getImdbVotesCount = $json['imdbVotes'];
		$getImdbBoxOffice = $json['BoxOffice'];
		$getImdbYear = $json['Year'];

        update_post_meta($post->ID, 'TR_GRABBER_FIELD_IMDBRATING', $getImdbRating);
        update_post_meta($post->ID, 'TR_GRABBER_FIELD_IMDBVOTESCOUNT', $getImdbVotesCount);
        update_post_meta($post->ID, 'TR_GRABBER_FIELD_IMDBBOXOFFICE', $getImdbBoxOffice);
        update_post_meta($post->ID, 'TR_GRABBER_FIELD_IMDBYEAR', $getImdbYear);
    }
}
// Hook into init action and run our function
add_action('init','update_my_metadata');