1.\" Copyright (c) 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the Institute of Electrical and Electronics Engineers, Inc. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)touch.1 8.3 (Berkeley) 4/28/95 36.\" 37.Dd April 28, 1995 38.Dt TOUCH 1 39.Os 40.Sh NAME 41.Nm touch 42.Nd change file access and modification times 43.Sh SYNOPSIS 44.Nm 45.Op Fl acfm 46.Op Fl r Ar file 47.Op Fl t Ar [[CC]YY]MMDDhhmm[.SS] 48.Ar 49.Sh DESCRIPTION 50The 51.Nm 52utility sets the modification and access times of files to the 53current time of day. 54If the file doesn't exist, it is created with default permissions. 55.Pp 56The following options are available: 57.Bl -tag -width Ds 58.It Fl a 59Change the access time of the file. 60The modification time of the file is not changed unless the 61.Fl m 62flag is also specified. 63.It Fl c 64Do not create the file if it does not exist. 65The 66.Nm 67utility does not treat this as an error. 68No error messages are displayed and the exit value is not affected. 69.It Fl f 70Attempt to force the update, even if the file permissions do not 71currently permit it. 72.It Fl m 73Change the modification time of the file. 74The access time of the file is not changed unless the 75.Fl a 76flag is also specified. 77.It Fl r 78Use the access and modifications times from the specified file 79instead of the current time of day. 80.It Fl t 81Change the access and modification times to the specified time. 82The argument should be in the form 83.Dq [[CC]YY]MMDDhhmm[.SS] 84where each pair of letters represents the following: 85.Pp 86.Bl -tag -width Ds -compact -offset indent 87.It Ar CC 88The first two digits of the year (the century). 89.It Ar YY 90The second two digits of the year. 91If 92.Dq YY 93is specified, but 94.Dq CC 95is not, a value for 96.Dq YY 97between 69 and 99 results in a 98.Dq CC 99value of 19. 100Otherwise, a 101.Dq CC 102value of 20 is used. 103.It Ar MM 104The month of the year, from 1 to 12. 105.It Ar DD 106the day of the month, from 1 to 31. 107.It Ar hh 108The hour of the day, from 0 to 23. 109.It Ar mm 110The minute of the hour, from 0 to 59. 111.It Ar SS 112The second of the minute, from 0 to 61. 113.El 114.Pp 115If the 116.Dq CC 117and 118.Dq YY 119letter pairs are not specified, the values default to the current 120year. 121If the 122.Dq SS 123letter pair is not specified, the value defaults to 0. 124.El 125.Pp 126The 127.Nm 128utility exits 0 on success, and >0 if an error occurs. 129.Sh SEE ALSO 130.Xr utimes 2 131.Sh COMPATIBILITY 132The obsolescent form of 133.Nm touch , 134where a time format is specified as the first argument, is supported. 135When no 136.Fl r 137or 138.Fl t 139option is specified, there are at least two arguments, and the first 140argument is a string of digits either eight or ten characters in length, 141the first argument is interpreted as a time specification of the form 142.Dq MMDDhhmm[YY] . 143.Pp 144The 145.Dq MM , 146.Dq DD , 147.Dq hh 148and 149.Dq mm 150letter pairs are treated as their counterparts specified to the 151.Fl t 152option. 153If the 154.Dq YY 155letter pair is in the range 39 to 99, the year is set to 1939 to 1999, 156otherwise, the year is set in the 21st century. 157.Sh HISTORY 158A 159.Nm 160utility appeared in 161.At v7 . 162.Sh STANDARDS 163The 164.Nm 165utility is expected to be a superset of the 166.St -p1003.2 167specification. 168