given command is executed; after it is complete,
prints the elapsed time during the command, the time
spent in the system, and the time spent in execution
Times are reported in seconds.
On a PDP-11, the execution time can depend on what kind of memory
the program happens to land in;
the user time in MOS is often half what it is in core.
The times are printed on the diagnostic output stream.
Elapsed time is accurate to the second,
while the CPU times are measured
Thus the sum of the CPU times can be up to a second larger