[nachos@os userprog]$ ./nachos -x ../test/shell
--../test/shell
--../test/halt
Machine halting!

Ticks: total 1678, idle 0, system 1270, user 408
Disk I/O: reads 0, writes 0
Console I/O: reads 13, writes 1
Paging: faults 0
Network I/O: packets received 0, sent 0

Cleaning up...