note that umask is applied to mkdir perms

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@50847 c90b9560-bf6c-de11-be94-00142212c4b1

functions/filesystem.xml

@@ -2064,6 +2064,8 @@ if($fp){
     <para>
      Note that you probably want to specify the mode as an
      octal number, which means it should have a leading zero.
+     The mode is also modified by the current umask, which you
+     can change using <function>umask</function>.
      <informalexample>
       <programlisting role="php">
 mkdir ("/path/to/my/dir", 0700);