1.\" $NetBSD: touch.1,v 1.16 2003/08/07 11:16:44 agc 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 April 28, 1995 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 68Attempt to force the update, even if the file permissions do not 69currently permit it. 70.It Fl h 71If 72.Ar file 73is a symbolic link, access and/or modification time of the link is changed. 74This option implies 75.Fl c . 76.It Fl m 77Change the modification time of the file. 78The access time of the file is not changed unless the 79.Fl a 80flag is also specified. 81.It Fl r 82Use the access and modifications times from the specified file 83instead of the current time of day. 84.It Fl t 85Change the access and modification times to the specified time. 86The argument should be in the form 87.Dq [[CC]YY]MMDDhhmm[.SS] 88where each pair of letters represents the following: 89.Pp 90.Bl -tag -width Ds -compact -offset indent 91.It Ar CC 92The first two digits of the year (the century). 93.It Ar YY 94The second two digits of the year. 95If 96.Dq YY 97is specified, but 98.Dq CC 99is not, a value for 100.Dq YY 101between 69 and 99 results in a 102.Dq CC 103value of 19. 104Otherwise, a 105.Dq CC 106value of 20 is used. 107.It Ar MM 108The month of the year, from 1 to 12. 109.It Ar DD 110The day of the month, from 1 to 31. 111.It Ar hh 112The hour of the day, from 0 to 23. 113.It Ar mm 114The minute of the hour, from 0 to 59. 115.It Ar SS 116The second of the minute, from 0 to 61. 117.El 118.Pp 119If the 120.Dq CC 121and 122.Dq YY 123letter pairs are not specified, the values default to the current 124year. 125If the 126.Dq SS 127letter pair is not specified, the value defaults to 0. 128.El 129.Pp 130The 131.Nm 132utility exits 0 on success, and \*[Gt]0 if an error occurs. 133.Sh SEE ALSO 134.Xr utimes 2 135.Sh COMPATIBILITY 136The obsolescent form of 137.Nm , 138where a time format is specified as the first argument, is supported. 139When no 140.Fl r 141or 142.Fl t 143option is specified, there are at least two arguments, and the first 144argument is a string of digits either eight or ten characters in length, 145the first argument is interpreted as a time specification of the form 146.Dq MMDDhhmm[YY] . 147.Pp 148The 149.Dq MM , 150.Dq DD , 151.Dq hh 152and 153.Dq mm 154letter pairs are treated as their counterparts specified to the 155.Fl t 156option. 157If the 158.Dq YY 159letter pair is in the range 69 to 99, the year is set to 1969 to 1999, 160otherwise, the year is set in the 21st century. 161.Sh STANDARDS 162The 163.Nm 164utility is expected to be a superset of the 165.St -p1003.2 166specification. 167.Sh HISTORY 168A 169.Nm 170utility appeared in 171.At v7 . 172.Sh BUGS 173A symbolic link can't be a reference file of access and/or modification time. 174