MAX_PROCTITLE
static char buf[MAX_PROCTITLE], *bufp = buf;
used = snprintf(buf, MAX_PROCTITLE, "%s: ", __progname);
if (used >= MAX_PROCTITLE)
used = MAX_PROCTITLE - 1;
(void)vsnprintf(buf + used, MAX_PROCTITLE - used, fmt, ap);
(void)snprintf(buf, MAX_PROCTITLE, "%s", __progname);