dd_write_msg
dd_write_msg(arg, 0);
int dd_write_msg(const char *, int);
dd_write_msg(msgfmt, 1);
(void)dd_write_msg("%I+%i records in\n%O+%o records out\n", 1);
(void)dd_write_msg("%w odd length swab %W\n", 1);
(void)dd_write_msg("%t truncated %T\n", 1);
(void)dd_write_msg("%p sparse output %P\n", 1);
(void)dd_write_msg("%b bytes (%B) transferred in %s secs "