is_dir returns false even when it is a dir?
<p>Why does is_dir() return false even if it is a dir?</p>

<p>returns no error</p>

<pre><code>$path_mysql = '/var/lib/mysql/';
if(!is_dir($path_mysql)){
    echo 'error';
}
</code></pre>

<p>returns error</p>

<pre><code>$path_mysql = '/var/lib/mysql/domain.com/';
if(!is_dir($path_mysql)){
    echo 'error';
}
</code></pre>

<p><code>/var/lib/mysql/domain.com/</code> does exsits, but is_dir() returns false!?</p>

<p>I can get access to the dir through both PuTTY and WinSCP</p>
