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 termination.

	   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 unspecified, 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
user %f
sys %f
 < 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 commands. 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_MES-
       SAGES, 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
       following 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 displayed may not always be accurate.

BUGS

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

SunOS 5.11							    1 Feb 1995								   time(1)