diff --git a/lib/util.php b/lib/util.php
index 469f132b8e..1ae43a0563 100644
--- a/lib/util.php
+++ b/lib/util.php
@@ -1104,15 +1104,20 @@ function common_ensure_syslog()
     }
 }
 
+function common_log_line($priority, $msg)
+{
+    static $syslog_priorities = array('LOG_EMERG', 'LOG_ALERT', 'LOG_CRIT', 'LOG_ERR',
+                                      'LOG_WARNING', 'LOG_NOTICE', 'LOG_INFO', 'LOG_DEBUG');
+    return date('Y-m-d H:i:s') . ' ' . $syslog_priorities[$priority] . ': ' . $msg . "\n";
+}
+
 function common_log($priority, $msg, $filename=null)
 {
     $logfile = common_config('site', 'logfile');
     if ($logfile) {
         $log = fopen($logfile, "a");
         if ($log) {
-            static $syslog_priorities = array('LOG_EMERG', 'LOG_ALERT', 'LOG_CRIT', 'LOG_ERR',
-                                              'LOG_WARNING', 'LOG_NOTICE', 'LOG_INFO', 'LOG_DEBUG');
-            $output = date('Y-m-d H:i:s') . ' ' . $syslog_priorities[$priority] . ': ' . $msg . "\n";
+            $output = common_log_line($priority, $msg);
             fwrite($log, $output);
             fclose($log);
         }