and tags as well as any
//whitespace.
?>
LABORatorio Revelli - WHIP Data House
As the subject mentions, is fwrite method atomic in PHP? What I mean
//> by that is, does fwrite function acquire an implicit lock while
//> writing or do I need to explicitly acquire an EXCLUSIVE lock on the
//> file before I call fwrite?
//
//That depends on your mode. If you opened the file in append mode, then
//yes, it is atomic. On some operating systems that may or may not be
//true over network filesystems like NFS if you are writing more than a
//block size, but if it is a local fs and you are in append mode, you can
//count on it being atomic. If you are not in append mode, then it is not
//atomic at all.
//
//> The problem I am having is that, I want to track user requests by
//> logging simple request parameters such as user IP, request URI, etc.
//> instead of inserting into the db for avoiding overheads. And I will
//> have a cronjob read this data around midnight and write it into the
//> database (when there is little load on the server).
//
//For straight logging like this you should be able to simply append to
//the log file and thus your fwrite will be atomic.
*/
fputs($handle, $ln);
}
if(!isset($HTTP_COOKIE_VARS["whip-session"])) {
$handle = fopen($fn_today, "a+");
$line = "[" . $_SERVER['REMOTE_ADDR'] . "] | [$uid] | ". date("YmdHis ") . " | [" . $_SERVER['HTTP_USER_AGENT'] ."]\n";
atomic_fwrite($handle,$line);
fclose($handle);
}
?>
<![CDATA[ sorry, you need frames to browse this site ]]>