/usr.bin/touch/touch.1

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 31.\"     @(#)touch.1	8.3 (Berkeley) 4/28/95
 32.\" $FreeBSD$
 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 .