popsu-d7/sites/all/modules/imagecache_actions/autorotate/imagecache_autorotate.install

<?php
/**
 * @file (un)install and (dis/en)able hooks for imagecache autorotate module.
 */

/**
 * Implements hook_enable().
 */
function imagecache_autorotate_enable() {
  if (!function_exists('exif_read_data')) {
    drupal_set_message(t('The exif_read_data() function is not available in this PHP installation. You probably will have to enable the exif extension.'), 'warning');
  }
}