EDIT

/**

 * implements hook_install()

 */

function ext_links_install() {

  $links_templates = migrate_old_ext_links();

  foreach ($links_templates as $ext_link){

    db_delete('variable')

      ->condition('name', "ext_links_" . $ext_link->id . '_%', 'LIKE')

      ->execute();

  }

}

 * Migrates old ext link templates from drupal vars to the ext_link table.

  $links_templates = ext_links_templates();

  foreach ($links_templates as $ext_link){

    $ext_link = _ext_links_merge_old_vars($ext_link);

    ext_links_save($ext_link);

  }

  return $links_templates;

  $ext_link->status = variable_get("ext_links_${ext_link_id}_check", $ext_link->id);

  $ext_link->link =  variable_get("ext_links_${ext_link_id}_link", $ext_link->link);

  $ext_link->glue = variable_get("ext_links_${ext_link_id}_concat",   $ext_link->glue);

  $ext_link->title = variable_get("ext_links_${ext_link_id}_text", $ext_link->title);