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. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)touch.1 8.3 (Berkeley) 4/28/95 32.\" $FreeBSD: src/usr.bin/touch/touch.1,v 1.21 2012/11/17 01:54:31 svnexp Exp $ 33.\" 34.Dd June 10, 2012 35.Dt TOUCH 1 36.Os 37.Sh NAME 38.Nm touch 39.Nd change file access and modification times 40.Sh SYNOPSIS 41.Nm 42.Op Fl A Ar [-][[hh]mm]SS 43.Op Fl achm 44.Op Fl r Ar file 45.Op Fl t Ar [[CC]YY]MMDDhhmm[.SS] 46.Op Fl d Ar YYYY-MM-DDThh:mm:SS[.frac][tz] 47.Ar 48.Sh DESCRIPTION 49The 50.Nm 51utility sets the modification and access times of files. 52If any file does not exist, it is created with default permissions. 53.Pp 54By default, 55.Nm 56changes both modification and access times. The 57.Fl a 58and 59.Fl m 60flags may be used to select the access time or the modification time 61individually. 62Selecting both is equivalent to the default. 63By default, the timestamps are set to the current time. 64The 65.Fl d 66and 67.Fl t 68flags explicitly specify a different time, and the 69.Fl r 70flag specifies to set the times those of the specified file. 71The 72.Fl A 73flag adjusts the values by a specified amount. 74.Pp 75The following options are available: 76.Bl -tag -width Ds 77.It Fl A 78Adjust the access and modification time stamps for the file by the 79specified value. 80This flag is intended for use in modifying files with incorrectly set 81time stamps. 82.Pp 83The argument is of the form 84.Dq [-][[hh]mm]SS 85where each pair of letters represents the following: 86.Pp 87.Bl -tag -width Ds -compact -offset indent 88.It Ar - 89Make the adjustment negative: the new time stamp is set to be before 90the old one. 91.It Ar hh 92The number of hours, from 00 to 99. 93.It Ar mm 94The number of minutes, from 00 to 59. 95.It Ar SS 96The number of seconds, from 00 to 59. 97.El 98.Pp 99The 100.Fl A 101flag implies the 102.Fl c 103flag: if any file specified does not exist, it will be silently ignored. 104.It Fl a 105Change the access time of the file. 106The modification time of the file is not changed unless the 107.Fl m 108flag is also specified. 109.It Fl c 110Do not create the file if it does not exist. 111The 112.Nm 113utility does not treat this as an error. 114No error messages are displayed and the exit value is not affected. 115.It Fl d 116Change the access and modification times to the specified time instead 117of the current time of day. 118The argument is of the form 119.Dq YYYY-MM-DDThh:mm:SS[.frac][tz] 120where the letters represent the following: 121.Bl -tag -width Ds -compact -offset indent 122.It Ar YYYY 123The year. 124.It Ar MM 125The month of the year, from 01 to 12. 126.It Ar DD 127The day of the month, from 01 to 31. 128.It Ar T 129The letter 130.Li T 131or a space. 132.It Ar hh 133The hour of the day, from 00 to 23. 134.It Ar mm 135The minute of the hour, from 00 to 59. 136.It Ar SS 137The second of the minute, from 00 to 61. 138.It Ar .frac 139An optional fraction, 140consisting of a period or a comma followed by one or more digits. 141The number of significant digits depends on the kernel configuration and 142the filesystem, and may be zero. 143.It Ar tz 144An optional letter 145.Li Z 146indicating the time is in 147.Tn UTC . 148Otherwise, the time is assumed to be in local time. 149.El 150.It Fl h 151If the file is a symbolic link, change the times of the link 152itself rather than the file that the link points to. 153Note that 154.Fl h 155implies 156.Fl c 157and thus will not create any new files. 158.It Fl m 159Change the modification time of the file. 160The access time of the file is not changed unless the 161.Fl a 162flag is also specified. 163.It Fl r 164Use the access and modifications times from the specified file 165instead of the current time of day. 166.It Fl t 167Change the access and modification times to the specified time instead 168of the current time of day. 169The argument is of the form 170.Dq [[CC]YY]MMDDhhmm[.SS] 171where each pair of letters represents the following: 172.Pp 173.Bl -tag -width Ds -compact -offset indent 174.It Ar CC 175The first two digits of the year (the century). 176.It Ar YY 177The second two digits of the year. 178If 179.Dq YY 180is specified, but 181.Dq CC 182is not, a value for 183.Dq YY 184between 69 and 99 results in a 185.Dq CC 186value of 19. 187Otherwise, a 188.Dq CC 189value of 20 is used. 190.It Ar MM 191The month of the year, from 01 to 12. 192.It Ar DD 193the day of the month, from 01 to 31. 194.It Ar hh 195The hour of the day, from 00 to 23. 196.It Ar mm 197The minute of the hour, from 00 to 59. 198.It Ar SS 199The second of the minute, from 00 to 61. 200.El 201.Pp 202If the 203.Dq CC 204and 205.Dq YY 206letter pairs are not specified, the values default to the current 207year. 208If the 209.Dq SS 210letter pair is not specified, the value defaults to 0. 211.El 212.Sh EXIT STATUS 213.Ex -std 214.Sh COMPATIBILITY 215The obsolescent form of 216.Nm , 217where a time format is specified as the first argument, is supported. 218When no 219.Fl r 220or 221.Fl t 222option is specified, there are at least two arguments, and the first 223argument is a string of digits either eight or ten characters in length, 224the first argument is interpreted as a time specification of the form 225.Dq MMDDhhmm[YY] . 226.Pp 227The 228.Dq MM , 229.Dq DD , 230.Dq hh 231and 232.Dq mm 233letter pairs are treated as their counterparts specified to the 234.Fl t 235option. 236If the 237.Dq YY 238letter pair is in the range 39 to 99, the year is set to 1939 to 1999, 239otherwise, the year is set in the 21st century. 240.Sh SEE ALSO 241.Xr utimes 2 242.Sh STANDARDS 243The 244.Nm 245utility is expected to be a superset of the 246.St -p1003.2 247specification. 248.Sh HISTORY 249A 250.Nm 251utility appeared in 252.At v7 . 253