1.\" $NetBSD: touch.1,v 1.18 2011/02/22 15:47:02 wiz Exp $ 2.\" 3.\" Copyright (c) 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" the Institute of Electrical and Electronics Engineers, Inc. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" @(#)touch.1 8.3 (Berkeley) 4/28/95 34.\" 35.Dd February 22, 2011 36.Dt TOUCH 1 37.Os 38.Sh NAME 39.Nm touch 40.Nd change file access and modification times 41.Sh SYNOPSIS 42.Nm 43.Op Fl acfhm 44.Op Fl r Ar file 45.Op Fl t Ar [[CC]YY]MMDDhhmm[.SS] 46.Ar file ... 47.Sh DESCRIPTION 48The 49.Nm 50utility sets the modification and access times of files to the 51current time of day. 52If the file doesn't exist, it is created with default permissions. 53.Pp 54The following options are available: 55.Bl -tag -width Ds 56.It Fl a 57Change the access time of the file. 58The modification time of the file is not changed unless the 59.Fl m 60flag is also specified. 61.It Fl c 62Do not create the file if it does not exist. 63The 64.Nm 65utility does not treat this as an error. 66No error messages are displayed and the exit value is not affected. 67.It Fl f 68This flag has no effect; it is accepted for compatibility reasons. 69.It Fl h 70If 71.Ar file 72is a symbolic link, access and/or modification time of the link is changed. 73This option implies 74.Fl c . 75.It Fl m 76Change the modification time of the file. 77The access time of the file is not changed unless the 78.Fl a 79flag is also specified. 80.It Fl r 81Use the access and modifications times from the specified file 82instead of the current time of day. 83.It Fl t 84Change the access and modification times to the specified time. 85The argument should be in the form 86.Dq [[CC]YY]MMDDhhmm[.SS] 87where each pair of letters represents the following: 88.Pp 89.Bl -tag -width Ds -compact -offset indent 90.It Ar CC 91The first two digits of the year (the century). 92.It Ar YY 93The second two digits of the year. 94If 95.Dq YY 96is specified, but 97.Dq CC 98is not, a value for 99.Dq YY 100between 69 and 99 results in a 101.Dq CC 102value of 19. 103Otherwise, a 104.Dq CC 105value of 20 is used. 106.It Ar MM 107The month of the year, from 1 to 12. 108.It Ar DD 109The day of the month, from 1 to 31. 110.It Ar hh 111The hour of the day, from 0 to 23. 112.It Ar mm 113The minute of the hour, from 0 to 59. 114.It Ar SS 115The second of the minute, from 0 to 61. 116.El 117.Pp 118If the 119.Dq CC 120and 121.Dq YY 122letter pairs are not specified, the values default to the current 123year. 124If the 125.Dq SS 126letter pair is not specified, the value defaults to 0. 127.El 128.Pp 129The 130.Nm 131utility exits 0 on success, and \*[Gt]0 if an error occurs. 132.Sh COMPATIBILITY 133The obsolescent form of 134.Nm , 135where a time format is specified as the first argument, is supported. 136When no 137.Fl r 138or 139.Fl t 140option is specified, there are at least two arguments, and the first 141argument is a string of digits either eight or ten characters in length, 142the first argument is interpreted as a time specification of the form 143.Dq MMDDhhmm[YY] . 144.Pp 145The 146.Dq MM , 147.Dq DD , 148.Dq hh 149and 150.Dq mm 151letter pairs are treated as their counterparts specified to the 152.Fl t 153option. 154If the 155.Dq YY 156letter pair is in the range 69 to 99, the year is set to 1969 to 1999, 157otherwise, the year is set in the 21st century. 158.Sh SEE ALSO 159.Xr utimes 2 160.Sh STANDARDS 161The 162.Nm 163utility is expected to be a superset of the 164.St -p1003.2 165specification. 166.Sh HISTORY 167A 168.Nm 169utility appeared in 170.At v7 . 171.Sh BUGS 172A symbolic link can't be a reference file of access and/or modification time. 173