TIME(1) 						    BSD General Commands Manual 						   TIME(1)

NAME

     time -- time command execution

SYNOPSIS

     time [-clp] command [argument ...]

DESCRIPTION

     The time utility executes and times command.  After the command finishes, time writes the total elapsed time (wall clock time), (``real''),
     the CPU time spent executing command at user level (``user''), and the CPU time spent executing in the operating system kernel (``sys''), to
     the standard error stream.  Times are reported in seconds.

     Available options:

     -c      Displays information in the format used by the time builtin of csh(1).

     -l      Lists resource utilization information.  The contents of the command process's rusage structure are printed; see below.

     -p      The output is formatted as specified by IEEE Std 1003.2-1992 (``POSIX.2'').

     Some shells, such as csh(1) and ksh(1), have their own and syntactically different built-in version of time.  The utility described here is
     available as /usr/bin/time to users of these shells.

   Resource Utilization
     If the -l option is given, the following resource usage information is displayed in addition to the timing information:
	   maximum resident set size
	   average shared memory size
	   average unshared data size
	   average unshared stack size
	   page reclaims
	   page faults
	   swaps
	   block input operations
	   block output operations
	   messages sent
	   messages received
	   signals received
	   voluntary context switches
	   involuntary context switches
     Resource usage is the total for the execution of command and any child processes it spawns, as per wait4(2).

FILES

     <sys/resource.h>

EXIT STATUS

     The time utility exits with one of the following values:

     1-125   An error occurred in the time utility.

     126     The command was found but could not be invoked.

     127     The command could not be found.

     Otherwise, the exit status of time will be that of command.

SEE ALSO

     csh(1), ksh(1), clock_gettime(2), getrusage(2)

STANDARDS

     The time utility conforms to IEEE Std 1003.2-1992 (``POSIX.2'').

BUGS

     The granularity of seconds on microprocessors is crude and can result in times being reported for CPU usage which are too large by a second.

BSD
								 November 9, 2011							       BSD