What causes PHP's error_log to log to both a file and standard output w/CLI execution?
<p>I have two servers, from what I can tell from comparing php -i outputs, they are configured almost identically. This isn't an error logging question, that's all working/setup fine.</p>

<p>What I can't understand, is why this command differs between the two servers:</p>

<pre><code>php -r "error_log('test test test');"
</code></pre>

<p>Server one, the output is appended to the error log AND outputted to STDERR in the terminal:</p>

<pre><code>$ php -r "error_log('test test test');"
test test test
$ php -r "error_log('test test test');" 2&gt;/dev/null
$
</code></pre>

<p>On server two, no output, it's only appended to the error log:</p>

<pre><code>$ php -r "error_log('test test test');"
$
</code></pre>

<p>I like this behavior of server one as I can use error_log in my scripts and have that logged AND echoed to the terminal for info/debugging. Any ideas/suggestions on what configuration, or extension, might be enabling this functionality in the PHP CLI?</p>
