Find out the time taken for a commands execution

time ls -l
yieldsCode:

real 0m0.047s
user 0m0.004s
sys 0m0.000s

This indicates that as far as I could perceive it, it took about 50 milliseconds to execute, of which the commands REALLY ran for about 4 milliseconds in user space. Since the "ls" command doesnt' need anything from the system(kernel) to complete, the "sys" time is zero.

Run the command on a task that might take a little longer and start counting the seconds, and you'll find that the "real" portion will be inline with what you think has elapsed while the "sys" and "user" will tell you where the command was spending tmie..