— Function: void closelog (void)

closelog closes the current Syslog connection, if there is one. This includes closing the dev/log socket, if it is open. closelog also sets the identification string for Syslog messages back to the default, if openlog was called with a non-NULL argument to ident. The default identification string is the program name taken from argv[0].

If you are writing shared library code that uses openlog to generate custom syslog output, you should use closelog to drop the GNU C Library's internal reference to the ident pointer when you are done. Please read the section on openlog for more information: See openlog.

closelog does not flush any buffers. You do not have to call closelog before re-opening a Syslog connection with openlog. Syslog connections are automatically closed on exec or exit.