sys/kern/kern_sendfile.c

694 	off_t off, sbytes, rem, obj_size, nobj_size;
708 	hdrlen = sbytes = 0;
1201 		sbytes += space + hdrlen;
1217 			sbytes += td->td_retval[0];
1232 		(*sent) = sbytes;
1271 	off_t sbytes;
1281 	sbytes = 0;
1325 	    uap->nbytes, &sbytes, uap->flags, td);
1328 	if (uap->sbytes != NULL)
1329 		copyout(&sbytes, uap->sbytes, sizeof(off_t));
1341  *       struct sf_hdtr *hdtr, off_t *sbytes, int flags)
1346  * specified, write the total number of bytes sent into *sbytes.
1366 	args.sbytes = uap->sbytes;