PRT_NULL_OFLAG
fd = open("/dev/null", PRT_NULL_OFLAG);
if (!pr_target_check_fd("normal open", PRT_NULL_FD, PRT_NULL_OFLAG,
#define PRT_DUP_OFLAG PRT_NULL_OFLAG
#define PRT_CLOFORK_OFLAG PRT_NULL_OFLAG