1.\" $NetBSD: touch.1,v 1.6 1994/12/07 09:19:48 jtc 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. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the University of 20.\" California, Berkeley and its contributors. 21.\" 4. Neither the name of the University nor the names of its contributors 22.\" may be used to endorse or promote products derived from this software 23.\" without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35.\" SUCH DAMAGE. 36.\" 37.\" @(#)touch.1 8.2 (Berkeley) 12/30/93 38.\" 39.Dd December 7, 1994 40.Dt TOUCH 1 41.Os 42.Sh NAME 43.Nm touch 44.Nd change file access and modification times 45.Sh SYNOPSIS 46.Nm touch 47.Op Fl acfm 48.Op Fl r Ar file 49.Op Fl t Ar [[CC]YY]MMDDhhmm[.SS] 50.Ar file ... 51.Sh DESCRIPTION 52The 53.Nm touch 54utility sets the modification and access times of files to the 55current time of day. 56If the file doesn't exist, it is created with default permissions. 57.Pp 58The following options are available: 59.Bl -tag -width Ds 60.It Fl a 61Change the access time of the file. 62The modification time of the file is not changed unless the 63.Fl m 64flag is also specified. 65.It Fl c 66Do not create the file if it does not exist. 67The 68.Nm touch 69utility does not treat this as an error. 70No error messages are displayed and the exit value is not affected. 71.It Fl f 72Attempt to force the update, even if the file permissions do not 73currently permit it. 74.It Fl m 75Change the modification time of the file. 76The access time of the file is not changed unless the 77.Fl a 78flag is also specified. 79.It Fl r 80Use the access and modifications times from the specified file 81instead of the current time of day. 82.It Fl t 83Change the access and modification times to the specified time. 84The argument should be in the form 85.Dq [[CC]YY]MMDDhhmm[.SS] 86where each pair of letters represents the following: 87.Pp 88.Bl -tag -width Ds -compact -offset indent 89.It Ar CC 90The first two digits of the year (the century). 91.It Ar YY 92The second two digits of the year. 93If 94.Dq YY 95is specified, but 96.Dq CC 97is not, a value for 98.Dq YY 99between 69 and 99 results in a 100.Dq YY 101value of 19. 102Otherwise, a 103.Dq YY 104value of 20 is used. 105.It Ar MM 106The month of the year, from 1 to 12. 107.It Ar DD 108the day of the month, from 1 to 31. 109.It Ar hh 110The hour of the day, from 0 to 23. 111.It Ar mm 112The minute of the hour, from 0 to 59. 113.It Ar SS 114The second of the minute, from 0 to 61. 115.El 116.Pp 117If the 118.Dq CC 119and 120.Dq YY 121letter pairs are not specified, the values default to the current 122year. 123If the 124.Dq SS 125letter pair is not specified, the value defaults to 0. 126.El 127.Pp 128The 129.Nm touch 130utility exits 0 on success, and >0 if an error occurs. 131.Sh SEE ALSO 132.Xr utimes 2 133.Sh COMPATIBILITY 134The obsolescent form of 135.Nm touch , 136where a time format is specified as the first argument, is supported. 137When no 138.Fl r 139or 140.Fl t 141option is specified, there are at least two arguments, and the first 142argument is a string of digits either eight or ten characters in length, 143the first argument is interpreted as a time specification of the form 144.Dq MMDDhhmm[YY] . 145.Pp 146The 147.Dq MM , 148.Dq DD , 149.Dq hh 150and 151.Dq mm 152letter pairs are treated as their counterparts specified to the 153.Fl t 154option. 155If the 156.Dq YY 157letter pair is in the range 69 to 99, the year is set to 1969 to 1999, 158otherwise, the year is set in the 21st century. 159.Sh HISTORY 160A 161.Nm touch 162utility appeared in 163.At v7 . 164.Sh STANDARDS 165The 166.Nm touch 167utility is expected to be a superset of the 168.St -p1003.2 169specification. 170