getmntoptnum
long getmntoptnum(mntoptparse_t, const char *);
port = (int)getmntoptnum(mp, "port");
(int)getmntoptnum(mp, "rsize");
(int)getmntoptnum(mp, "wsize");
(int)getmntoptnum(mp, "rdirsize");
(int)getmntoptnum(mp, "maxgrps");
(int)getmntoptnum(mp, "leaseterm");
(int)getmntoptnum(mp, "readahead");
(int)getmntoptnum(mp, "deadthresh");
(int)getmntoptnum(mp, "timeo");
(int)getmntoptnum(mp, "retrans");
args.mode = (mode_t)getmntoptnum(mp, "mode");
v = getmntoptnum(mp, "nconn");