1.\" $NetBSD: time.1,v 1.30 2021/04/05 23:01:55 pgoyette Exp $ 2.\" 3.\" Copyright (c) 1980, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)time.1 8.1 (Berkeley) 6/6/93 31.\" 32.Dd April 5, 2021 33.Dt TIME 1 34.Os 35.Sh NAME 36.Nm time 37.Nd time command execution 38.Sh SYNOPSIS 39.Nm 40.Op Fl clpt 41.Op Fl f Ar fmt 42.Ar command 43.Op Ar argument ... 44.Sh DESCRIPTION 45The 46.Nm 47utility 48executes and 49times 50.Ar command . 51After the command finishes, 52.Nm 53writes the total elapsed time (wall clock time), 54.Pq Dq real , 55the CPU time spent executing 56.Ar command 57at user level 58.Pq Dq user , 59and the CPU time spent executing in the operating system kernel 60.Pq Dq sys , 61to the standard error stream. 62Times are reported in seconds. 63.Pp 64Available options: 65.Bl -tag -width Ds 66.It Fl c 67Displays information in the format used by default the 68.Nm 69builtin of 70.Xr csh 1 71uses (%Uu %Ss %E %P %X+%Dk %I+%Oio %Fpf+%Ww). 72.It Fl f 73Specify a time format using the 74.Xr csh 1 75.Nm 76builtin syntax. 77The following sequences may be used in the format string: 78.Pp 79.Bl -tag -width 4n -compact 80.It \&%U 81The time the process spent in user mode in cpu seconds. 82.It \&%S 83The time the process spent in kernel mode in cpu seconds. 84.It \&%E 85The elapsed (wall clock) time in seconds. 86.It \&%P 87The CPU percentage computed as (%U + %S) / %E. 88.It \&%W 89Number of times the process was swapped. 90.It \&%X 91The average amount in (shared) text space used in Kbytes. 92.It \&%D 93The average amount in (unshared) data/stack space used in Kbytes. 94.It \&%K 95The total space used (%X + %D) in Kbytes. 96.It \&%M 97The maximum memory the process had in use at any time in Kbytes. 98.It \&%F 99The number of major page faults (page needed to be brought from disk). 100.It \&%R 101The number of minor page faults. 102.It \&%I 103The number of input operations. 104.It \&%O 105The number of output operations. 106.It \&%r 107The number of socket messages received. 108.It \&%s 109The number of socket messages sent. 110.It \&%k 111The number of signals received. 112.It \&%w 113The number of voluntary context switches (waits). 114.It \&%c 115The number of involuntary context switches. 116.El 117.It Fl l 118Lists resource utilization information. 119The contents of the 120.Ar command 121process's 122.Em rusage 123structure are printed; see below. 124.It Fl p 125The output is formatted as specified by 126.St -p1003.2-92 . 127.It Fl t 128Displays information in the format used by default the 129.Nm 130builtin of 131.Xr tcsh 1 132uses (%Uu %Ss %E %P\\t%X+%Dk %I+%Oio %Fpf+%Ww) with 133three decimal places for time values. 134.El 135.Pp 136Some shells, such as 137.Xr csh 1 138and 139.Xr ksh 1 , 140have their own and syntactically different built-in version of 141.Nm . 142The utility described here 143is available as 144.Pa /usr/bin/time 145to users of these shells. 146.Ss Resource Utilization 147If the 148.Fl l 149option is given, the following resource usage 150information is displayed 151in addition to the timing information: 152.Bl -item -offset indent -compact 153.It 154maximum resident set size 155.It 156average shared memory size 157.It 158average unshared data size 159.It 160average unshared stack size 161.It 162page reclaims 163.It 164page faults 165.It 166swaps 167.It 168block input operations 169.It 170block output operations 171.It 172messages sent 173.It 174messages received 175.It 176signals received 177.It 178voluntary context switches 179.It 180involuntary context switches 181.El 182Resource usage is the total for the execution of 183.Ar command 184and any child processes it spawns, as per 185.Xr wait4 2 . 186.Sh FILES 187.Bl -tag -width Xsys/resource.hX -compact 188.It Aq sys/resource.h 189.El 190.Sh EXIT STATUS 191The 192.Nm 193utility exits with one of the following values: 194.Bl -tag -width indent 195.It 1-125 196An error occurred in the 197.Nm 198utility. 199.It 126 200The 201.Ar command 202was found but could not be invoked. 203.It 127 204The 205.Ar command 206could not be found. 207.El 208.Pp 209Otherwise, the exit status of 210.Nm 211will be that of 212.Ar command . 213.Sh SEE ALSO 214.Xr csh 1 , 215.Xr ksh 1 , 216.Xr clock_gettime 2 , 217.Xr getrusage 2 , 218.Xr wait4 2 219.Sh STANDARDS 220The 221.Nm 222utility conforms to 223.St -p1003.2-92 . 224.Sh BUGS 225The granularity of seconds on microprocessors is crude and 226can result in times being reported for CPU usage which are too large by 227a second. 228