error_log not working as expected

Question

I have the following basic code:

<?php

    //http://localhost/error_log.php
    echo "write to the error_log";
    error_log("error_log entry");
    //error_log("error_log entry",0);

?>

When I navigate to this page, I see write to the error_log in the browser. It even appears in the access_log /var/log/apache2/access.log .

[my ip here] - - [18/Jan/2013:09:18:54 +0000] "GET /error_log.php HTTP/1.1" 200 314 "-" "Mozilla/5.0 (X11; Linux i686) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.97 Safari/537.11"

but when I check the error_log ie /var/log/apache2/error.log , I don't see either of the error_log messages.

Why are these not getting entered into the error_log?

Answer 1

You call it without a second parameter, this means default is 0

0   message is sent to PHP's system logger, using the Operating System's system logging mechanism or a file, depending on what the error_log configuration directive is set to. This is the default option.

Now it depends on the configuration of error_log .

If here is not "stderr", php will not log into the apache error log.

It seams to be "syslog" of this php send your log message to the syslog .

Now it depends on how you rsyslog.d is configurated.

But have look at folling logs

tail /var/log/syslog
tail /var/log/messages
tail /var/log/php
tail /var/log/php.log

You message should be in one of them.

Answer 2

error.log does not log anything unless error_log.php page makes an error.

access.log loges all the events that Apache Server process

That is the reason why your error.log does not log the event

check http://httpd.apache.org/docs/2.2/logs.html for more info