Publish all nodes of a type

publish_nodes.php

public function iPublishAllNodes($content_type) {
  $query = new EntityFieldQuery();
  $query->entityCondition('entity_type', 'node')
    ->entityCondition('bundle', $content_type);
  $result = $query->execute();
  if (isset($result['node'])) {
    $nids = array_keys($result['node']);
    $nodes = node_load_multiple($nids);
    foreach ($nodes as $node) {
      $node->status = 1;
      node_save($node);
    }
  }
}