1.20.x system.api.php hook_watchdog(array $log_entry)

Log an event message.

This hook allows modules to route log events to custom destinations, such as SMS, Email, pager, syslog, ...etc.


array $log_entry: An associative array containing the following keys:

  • type: The type of message for this entry.
  • user: The user object for the user who was logged in when the event happened.
  • request_uri: The request URI for the page the event happened in.
  • referer: The page that referred the user to the page where the event occurred.
  • ip: The IP address where the request for the page came from.
  • timestamp: The UNIX timestamp of the date/time the event occurred.
  • severity: The severity of the message; one of the following values as defined in RFC 3164:

  • link: An optional link provided by the module that called the watchdog() function.
  • message: The text of the message to be logged. Variables in the message are indicated by using placeholder strings alongside the variables argument to declare the value of the placeholders. See t() for documentation on how the message and variable parameters interact.
  • variables: An array of variables to be inserted into the message on display. Will be NULL or missing if a message is already translated or if the message is not possible to translate.

Related topics


modules/system/system.api.php, line 1831
Hooks provided by Backdrop core and the System module.


function hook_watchdog(array $log_entry) {
  global $base_url, $language;

  $severity_list = array(
    WATCHDOG_EMERGENCY => t('Emergency'),
    WATCHDOG_ALERT => t('Alert'),
    WATCHDOG_CRITICAL => t('Critical'),
    WATCHDOG_ERROR => t('Error'),
    WATCHDOG_WARNING => t('Warning'),
    WATCHDOG_NOTICE => t('Notice'),
    WATCHDOG_INFO => t('Info'),
    WATCHDOG_DEBUG => t('Debug'),
    WATCHDOG_DEPRECATED => t('Deprecated Use'),

  $to = 'someone@example.com';
  $params = array();
  $params['subject'] = t('[@site_name] @severity_desc: Alert from your web site', array(
    '@site_name' => config_get('system.core', 'site_name'),
    '@severity_desc' => $severity_list[$log_entry['severity']],

  $params['message'] = "\nSite:         @base_url";
  $params['message'] .= "\nSeverity:     (@severity) @severity_desc";
  $params['message'] .= "\nTimestamp:    @timestamp";
  $params['message'] .= "\nType:         @type";
  $params['message'] .= "\nIP Address:   @ip";
  $params['message'] .= "\nRequest URI:  @request_uri";
  $params['message'] .= "\nReferrer URI: @referer_uri";
  $params['message'] .= "\nUser:         (@uid) @name";
  $params['message'] .= "\nLink:         @link";
  $params['message'] .= "\nMessage:      \n\n@message";

  $params['message'] = t($params['message'], array(
    '@base_url' => $base_url,
    '@severity' => $log_entry['severity'],
    '@severity_desc' => $severity_list[$log_entry['severity']],
    '@timestamp' => format_date($log_entry['timestamp']),
    '@type' => $log_entry['type'],
    '@ip' => $log_entry['ip'],
    '@request_uri' => $log_entry['request_uri'],
    '@referer_uri' => $log_entry['referer'],
    '@uid' => $log_entry['user']->uid,
    '@name' => $log_entry['user']->name,
    '@link' => strip_tags($log_entry['link']),
    '@message' => strip_tags($log_entry['message']),

  backdrop_mail('emaillog', 'entry', $to, $language, $params);