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TIME(1) 		     General Commands Manual			 TIME(1)

NAME
     time -- time command execution

SYNOPSIS
     time [-al] [-h | -p] [-o file] utility [argument ...]

DESCRIPTION
     The  time	utility  executes  and	times  the specified utility.  After the
     utility finishes, time writes to the standard error stream,  (in  seconds):
     the  total  time  elapsed, the time used to execute the utility process and
     the time consumed by system overhead.

     The following options are available:

     -a       If the -o flag is used, append to the specified file  rather  than
	      overwriting it.  Otherwise, this option has no effect.

     -h       Print times in a human friendly format.  Times are printed in min-
	      utes, hours, etc. as appropriate.

     -l       The contents of the rusage structure are printed as well.

     -o file  Write  the  output  to file instead of stderr.  If file exists and
	      the -a flag is not specified, the file will be overwritten.

     -p       Makes time output POSIX.2 compliant (each time is printed  on  its
	      own line).

     Some  shells may provide a builtin time command which is similar or identi-
     cal to this utility.  Consult the builtin(1) manual page.

     If time receives a SIGINFO (see the status argument  for  stty(1))  signal,
     the  current time the given command is running will be written to the stan-
     dard output.

ENVIRONMENT
     The PATH environment variable is used to locate the  requested  utility  if
     the name contains no `/' characters.

EXIT STATUS
     If  utility  could  be timed successfully, its exit status is returned.  If
     utility terminated abnormally, a warning message is output to  stderr.   If
     the  utility was found but could not be run, the exit status is 126.  If no
     utility could be found at all, the exit status is 127.  If time  encounters
     any other error, the exit status is between 1 and 125 included.

EXAMPLES
     Time the execution of ls(1) on an empty directory:

	   $ /usr/bin/time ls
		   0.00 real	     0.00 user	       0.00 sys

     Time  the	execution  of  the  cp(1)  command  and  store the result in the
     times.txt file.  Then execute the command again to make a new copy and  add
     the result to the same file:

	   $ /usr/bin/time -o times.txt cp source.iso copy1.iso
	   $ /usr/bin/time -a -o times.txt cp source.iso copy2.iso

     The times.txt file will contain the times of both commands:

	   $ cat times.txt
		   0.68 real	     0.00 user	       0.22 sys
		   0.67 real	     0.00 user	       0.21 sys

     Time  the sleep(1) command and show the results in a human friendly format.
     Show the contents of the rusage structure too:

	   $ /usr/bin/time -l -h -p sleep 5
	   real 5.01
	   user 0.00
	   sys 0.00
		    0  maximum resident set size
		    0  average shared memory size
		    0  average unshared data size
		    0  average unshared stack size
		   80  page reclaims
		    0  page faults
		    0  swaps
		    1  block input operations
		    0  block output operations
		    0  messages sent
		    0  messages received
		    0  signals received
		    3  voluntary context switches
		    0  involuntary context switches

SEE ALSO
     builtin(1), csh(1), getrusage(2), wait(2)

STANDARDS
     The time utility is expected to conform to ISO/IEC 9945-2:1993 ("POSIX.2")

HISTORY
     A time utility appeared in Version 3 AT&T UNIX.

FreeBSD ports 15.1		  July 7, 2020				 TIME(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=time&manpath=FreeBSD+15.1-RELEASE+and+Ports>

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