time(1) 						      General Commands Manual							   time(1)

NAME

       time - Times the execution of a command

SYNOPSIS

       time [-p] command [argument...]

       The  time  command prints the elapsed time during the execution of a command, the time spent in the system, and the time spent in execution
       of the command on the diagnostic output system.

									  Note

       The C shell has a built-in version of the time command.	If you are using the C shell, and want to guarantee that you are using the command
       described here, you must specify the full path /usr/bin/time.  See the csh(1) reference page for a description of the built-in command.

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       time:  XCU5.0

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

OPTIONS

       Writes the timing output to standard error.  This is the default.

OPERANDS

       The name of a command to be executed.  If command identifies any name specified as a special built in your applicable shell reference page,
       the results are undefined and unpredictable.  The argument to be passed to command.  See the appropriate reference pages for these  values.
       This parameter may include flags and arguments expected by command.

DESCRIPTION

       The  time  command prints the elapsed time during the execution of a command, the time spent in the system, and the time spent in execution
       of the command on the diagnostic output system. Time is reported in seconds.

       The time command (with a different format) is also built into csh.

NOTES

       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)

EXIT STATUS

       The time command returns the following exit values if the command could not be invoked: An error occurred in the time command.  The command
       specified by command was found but could not be invoked.  The command specified by command could not be found.

       If the command was successfully invoked, the exit status of time is the exit status of command.

EXAMPLES

       To measure the time required to run a program, enter: time a.out

	      This runs the program a.out and writes to the standard error output the amount of real, system, and user time  that  it  uses:  real
	      10.5 user   0.3 sys    3.6 To measure the time required by a complex command, enter: time sh -c 'complex-cmmand-line'

	      This runs all of the commands, which may include pipelines, and returns the time information for the entire series of commands.

ENVIRONMENT VARIABLES

       The  following environment variables affect the execution of time: Provides a default value for the internationalization variables that are
       unset or null. If LANG is unset or null, the corresponding value from the default locale is used.  If any of the internationalization vari-
       ables  contain  an  invalid setting, the utility behaves as if none of the variables had been defined.  If set to a non-empty string value,
       overrides the values of all the other internationalization variables.  Determines the locale for the interpretation of sequences  of  bytes
       of  text data as characters (for example, single-byte as opposed to multibyte characters in arguments).	Determines the locale for the for-
       mat and contents of diagnostic messages written to standard error.  Determines the location of message catalogues  for  the  processing	of
       LC_MESSAGES.  Determines the path used to locate command.

SEE ALSO

       Commands:  csh(1), ksh(1), Bourne shell sh(1b), POSIX shell sh(1p)

       Functions:  times(3)

       Standards:  standards(5)

																	   time(1)