closelog(关闭信息记录)
#include <syslog.h> void closelog(void);
openlog(准备做信息记录)
#include <syslog.h> void openlog(const char *ident, int option, int facility);
syslog(将信息记录至系统日志文件)
#include <syslog.h> void syslog(int priority, const char *format, ...);