* Inspect the total bytes read/written on a group.
*
* Set the variable pointed to by total_read_out to the total number of bytes
* ever read on grp, and the variable pointed to by total_written_out to the
* total number of bytes ever written on grp.
* Inspect the total bytes read/written on a group. * * Set the variable pointed to by total_read_out to the total number of bytes * ever read on grp, and the variable pointed to by total_written_out to the * total number of bytes ever written on grp.