Simple type the following command on a Unix, OS X or FreeBSD based system to find out the duration of execution of host command:
$ time date
Tue Dec 8 15:42:02 IST 2015 real 0m0.005s user 0m0.001s sys 0m0.003s
- The real time is nothing but time time elapsed between invocation of utility and its termination.
- The User CPU time, equivalent to the sum of the tms_utime and tms_cutime fields returned by the times() function defined in the System Interfaces volume of POSIX.1-2008 for the process in which utility is executed.
- The System CPU time, equivalent to the sum of the tms_stime and tms_cstime fields returned by the times() function for the process in which utility is executed.
To get information about resource utilization during the execution of the command date type:
$ /usr/bin/time -l date
Tue Dec 8 15:45:17 IST 2015 0.00 real 0.00 user 0.00 sys 696320 maximum resident set size 0 average shared memory size 0 average unshared data size 0 average unshared stack size 182 page reclaims 0 page faults 0 swaps 0 block input operations 0 block output operations 0 messages sent 0 messages received 0 signals received 0 voluntary context switches 11 involuntary context switches