sec2str
sec2str(lifetime->ia6t_preferred - t));
: sec2str(lifetime->ia6t_expire - t));
char *sec2str(time_t);
sec2str(lifetime->ia6t_preferred - t));
: sec2str(lifetime->ia6t_expire - t));
char *sec2str(time_t);
sec2str(rtm->rtm_rmx.rmx_expire - now));
static char *sec2str(time_t);
static char *sec2str(time_t);
sec2str(nbi->expire - now.tv_sec));