time(1) 맨 페이지 - 윈디하나의 솔라나라

개요

섹션
맨 페이지 이름
검색(S)

time(1)

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 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 for‐
             mat:

               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 ap‐
       plications  can  distinguish  "failure to find a utility" from "invoked
       utility exited with an error indication." The value 127 was chosen  be‐
       cause  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(7) 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(7) for descriptions of the following attributes:

       tab()  box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) ATTRIBUTE TYPEAT‐
       TRIBUTE VALUE _ Availabilitysystem/core-os _ Interface StabilityCommit‐
       ted _ StandardSee standards(7).


SEE ALSO
       csh(1), shell_builtins(1),  timex(1),  times(2),  attributes(7),  envi‐
       ron(7), standards(7)

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.

Oracle Solaris 11.4               1 Feb 1995                           time(1)
맨 페이지 내용의 저작권은 맨 페이지 작성자에게 있습니다.
RSS ATOM XHTML 5 CSS3