numarg
static long numarg(const char *, long, long);
blocksperfile = numarg("blocks per file", 1L, 0L);
ntrec = numarg("blocks per write", 1L, 1000L);
density = numarg("density", 10L, 327670L) / 10;
honorlevel = numarg("honor level", 0L, 10L);
readblksize = numarg("read block size", 0, 64) * 1024;
lflag = numarg("timeout (in seconds)", 1, 0);
readcache = numarg("read cache size", 0, 512);
tsize = numarg("tape size", 1L, 0L) * 12 * 10;
numarg(nbps, NBPS, <=);
numarg(ncyl, NCYL, <=);
numarg(nspt, NSPT, <=);
numarg(ntrk, NTRK, <=);
numarg(stepspercyl, STEPSPERCYL, <=);
numarg(gaplen, GAPLEN, <=);
numarg(fillbyte, FILLBYTE, <);
numarg(xfer_rate, XFER_RATE, <=);
numarg(interleave, INTERLEAVE, <=);