[CentOS] Timing a command

Sat Jan 26 00:05:40 UTC 2008
Scott Ehrlich <scott at MIT.EDU>

I want to keep track of how long a task is running.  Thinking it wouldn't 
take that long, I opted not to run time before it.  The fact that it is 
taking a long time, if I revisit the machine in the morning, what would be 
the best way to find out what time it ended?

In this case, I'm using mt to erase an lto3 tape - sudo mt -f /dev/st0 
erase.  But I'd like to use the knowledge from this question to track 
other events, too.

I feel like I should know this answer, but cannot think of the solution at 
the moment.

Thanks.

Scott