Example import PO file

<?php

/**
 * Reloads translation file for a given module.
 *
 * @param mixed $module
 *   Module(s) name(s). An array of strings or a string.
 * @param mixed $languages
 * @return array
 *   An array with a "success" key which is a boolean and a "query" key which
 *   describes the SQL query executed. If additional sql parameters where
 *   given, a string "WITH PARAMETERS (param1, param2, ...)" is appended to
 *   the sql. It is compatible with hook_update and hook_install return values.
 */

function rcp_utils_locale_import_po($modules = array(), $langcodes = array(), $mode = LOCALE_IMPORT_KEEP, $group = 'default', $filename = '') {
  $ret = array();

  if (!is_array($modules)) {
    $modules = array($modules);
  }

  if (!is_array($langcodes)) {
    $langcodes = array($langcodes);
  }

  foreach ($modules as $module) {
    foreach ($langcodes as $langcode) {
      $file = new stdClass();
      $file->filename = empty($filename) ? ($langcode . '.po') : ($filename . '.po');
      $file->uri = drupal_get_path('module', $module) . '/translations/' . $file->filename;
      $file->filemime = 'application/octet-stream';
      $success = _locale_import_po($file, $langcode, $mode, $group);
      $ret[] = array('success' => $success, 'query' => 'Reload ' . $module . ' translation file');
    }
  }

  return $ret;
}