How to summarize detailed system resource usage for given command on a Linux or Unix

1. User time
2. System time
3. Percent of CPU this command got
4. Elapsed time
5. Average shared text size
6. Average unshared data size
7. Average stack size
8. Average total size
9. Maximum resident set size
10. Average resident set size
11. Major (requiring I/O) page faults
12. Minor (reclaiming a frame) page faults
13. Voluntary context switches
14. Involuntary context switches
15. Swaps
16. File system inputs
17. File system outputs
18. Socket messages sent
19. Socket messages received
20. Signals delivered
21. Page size (bytes)
22. Exit status

The above describing the resources utilized by the current process or command and can be obtained by “time” command. It is defined as follows in sys/resource.h

/* taken from OSX/FreeBSD unix */
     struct rusage {
             struct timeval ru_utime; /* user time used */
             struct timeval ru_stime; /* system time used */
             long ru_maxrss;          /* max resident set size */
             long ru_ixrss;           /* integral shared text memory size */
             long ru_idrss;           /* integral unshared data size */
             long ru_isrss;           /* integral unshared stack size */
             long ru_minflt;          /* page reclaims */
             long ru_majflt;          /* page faults */
             long ru_nswap;           /* swaps */
             long ru_inblock;         /* block input operations */
             long ru_oublock;         /* block output operations */
             long ru_msgsnd;          /* messages sent */
             long ru_msgrcv;          /* messages received */
             long ru_nsignals;        /* signals received */
             long ru_nvcsw;           /* voluntary context switches */
             long ru_nivcsw;          /* involuntary context switches */
     };

Syntax

The syntax is as follows on Linux:

/usr/bin/time -v command
/usr/bin/time -v command arg1 arg2

The syntax is as follows on FreeBSD or OS X unix:

/usr/bin/time -l command
/usr/bin/time -l command arg1 arg2

Examples

Let us run host command on Linux to find out the resources utilized by the host command during execution:
$ /usr/bin/time -v host www.cyberciti.biz
Sample outputs:

Fig.01: Determine the duration of execution of a particular command on Linux with resource utilization

Let us run date command on OS X or FreeBSD Unix based system to find out the resources utilized by the date command during execution:
$ /usr/bin/time -l date
Sample outputs:

Fig.02: Determine the duration of execution of a particular command on Unix/OSX

A note about “/usr/bin/time” and time command

1. time is a shell command.
2. /usr/bin/time is an external command and provides additional information such as the resources utilized by a particular command.

For more information see man pages ksh(1).