Proccess time

Hi everybody
I need to find out the execution time of a proccess. how can I find it out?
Note that the proccess execution are snap.
Thanks in advance.

man 1 time

$ time ( perl -e 'for($i=0;$i<1000;$i++){}' )

real    0m0.004s
user    0m0.004s
sys     0m0.000s

Sorry, It's possible to explain me real, user, sys? my system has not any doc about it.
Thanks

Real: total time (felt time)
User: Time in user space (calculations, ...)
Sys: Time in Kernel space (disk IO, ...)

Note that any input delay (waiting for user input or a web server) will only add to Real and nothing to the other two.

pludi, really thanks.