How to turn off logging in log4c, which is the configuration parameter used in xml file

I am using log4c library with xml configuration 开发者_开发技巧log4crc and I need to figure out how to turn off/on logging. I could not find any document explaining the parameters in log4crc configuration file,

try seeting the log priority to "notset"

If that doesn't work then make sure the system can't find your log configuration file and unset the environment variables LOG4C_APPENDER and LOG4C_PRIORITY

You could not turn off through set_priority() as log4c enum does not have support for OFF, where as avail in logj