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time(1)				 User Commands			       time(1)

NAME
       time - time a simple command

SYNOPSIS
       time [-p] utility [argument...]

DESCRIPTION
       The  time  utility  invokes utility operand with	argument, and writes a
       message to standard error that lists timing statistics for utility. The
       message includes	the following information:

	 o  The	elapsed	(real) time between invocation of utility and its ter-
	    mination.

	 o  The	User CPU time, equivalent to the  sum  of  the	tms_utime  and
	    tms_cutime	fields	returned  by  the  times(2)  function  for the
	    process in which utility is	executed.

	 o  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.

       When time is used as part of a pipeline,	the times reported are unspec-
       ified,  except when it is the sole command within a grouping command in
       that pipeline. For example, the commands	on the left  are  unspecified;
       those on	the right report on utilities a	and c, respectively:

       time a |	b | c	   { time a } |	b | c
       a | b | time c	   a | b | (time c)

OPTIONS
       The following option is supported:

       -p	Writes	the  timing  output to standard	error in the following
		format:

		real %f\nuser %f\nsys %f\n < real seconds>, <user seconds>,
		<system	seconds>

OPERANDS
       The following operands are supported:

       utility	       The name	of the utility that is to be invoked.

       argument	       Any string to be	supplied as an argument	when  invoking
		       utility.

USAGE
       The  time  utility  returns  exit status	127 if an error	occurs so that
       applications can	distinguish "failure to	find a utility"	from  "invoked
       utility	exited	with  an  error	 indication." The value	127 was	chosen
       because it is not commonly used for other meanings. Most	utilities  use
       small values for	"normal	error conditions" and the values above 128 can
       be confused with	termination due	to receipt of a	signal.	The value  126
       was  chosen  in	a similar manner to indicate that the utility could be
       found, but not invoked.

EXAMPLES
       Example 1: Using	the time command

       It is frequently	desirable to apply time	to pipelines or	lists of  com-
       mands.  This  can  be  done by placing pipelines	and command lists in a
       single file. This single	file can then be invoked as a utility, and the
       time applies to everything in the file.

       Alternatively,  the  following  command	can be used to apply time to a
       complex command:

       example%	time sh	-c 'complex-command-line'

       Example 2: Using	time in	the csh	shell

       The following two examples show the differences between the csh version
       of  time	 and  the version in /usr/bin/time. These examples assume that
       csh is the shell	in use.

       example%	time find / -name csh.1	-print
       /usr/share/man/man1/csh.1
       95.0u 692.0s 1:17:52 16%	0+0k 0+0io 0pf+0w

       See csh(1) for an explanation of	the format of time output.

       example%	/usr/bin/time find / -name csh.1 -print
       /usr/share/man/man1/csh.1
       real  1:23:31.5
       user	1:33.2
       sys     11:28.2

ENVIRONMENT VARIABLES
       See environ(5) for descriptions of the following	environment  variables
       that affect the execution of time: LANG,	LC_ALL,	LC_CTYPE, LC_MESSAGES,
       LC_NUMERIC,  NLSPATH, and PATH.

EXIT STATUS
       If utility is invoked, the exit status of time will be the exit	status
       of  utility. Otherwise, the time	utility	will exit with one of the fol-
       lowing values:

       1-125	       An error	occurred in the	time utility.

       126	       utility was found but could not be invoked.

       127	       utility could not be found.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       csh(1), shell_builtins(1), timex(1), times(2), attributes(5),  environ(
       5), standards(5)

NOTES
       When  the time command is run on	a multiprocessor machine, the total of
       the values printed for user and sys can exceed real. This  is   because
       on  a  multiprocessor machine it	is possible to divide the task between
       the various processors.

       When the	command	being timed is interrupted,  the  timing  values  dis-
       played may not always be	accurate.

BUGS
       Elapsed	time  is  accurate to the second, while	the CPU	times are mea-
       sured to	the 100th second. Thus the sum of the CPU times	can be up to a
       second larger than the elapsed time.

SunOS 5.10			  1 Feb	1995			       time(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPERANDS | USAGE | EXAMPLES | ENVIRONMENT VARIABLES | EXIT STATUS | ATTRIBUTES | SEE ALSO | NOTES | BUGS

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