<programlisting>#include <syslog.h>
#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
#include <systemd/sd-journal.h>
#include <systemd/sd-daemon.h>
fprintf(log, "Hello World!\n");
fprintf(log, SD_WARNING "This is a warning!\n");
fclose(log);
+ return 0;
}</programlisting>
</refsect1>