error_log does not write to system logs about phpdesktop HOT 2 CLOSED

If the log_type == 3, and $destination is provided, then error_log DOES work. 
Example:

   error_log("You messed up!", 3, "/var/tmp/my-errors.log");

Refer to http://www.php.net/manual/en/function.error-log.php for more info.

The "log_file" option in settings.json is for application level logging.

PHP logging is a different thing and should not be mistaken with the logging set
through the settings.json file.

To set php log file set the "error_log" option in php.ini:
http://www.php.net/manual/en/errorfunc.configuration.php#ini.error-log

I've updated the Settings wiki page and put a note for the log_file option:
https://code.google.com/p/phpdesktop/wiki/Settings