xref: /freebsd/usr.bin/touch/touch.1 (revision 123af6ec70016f5556da5972d4d63c7d175c06d3)
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31.\"     @(#)touch.1	8.3 (Berkeley) 4/28/95
32.\" $FreeBSD$
33.\"
34.Dd June 1, 2018
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.
57The
58.Fl a
59and
60.Fl m
61flags may be used to select the access time or the modification time
62individually.
63Selecting both is equivalent to the default.
64By default, the timestamps are set to the current time.
65The
66.Fl d
67and
68.Fl t
69flags explicitly specify a different time, and the
70.Fl r
71flag specifies to set the times those of the specified file.
72The
73.Fl A
74flag adjusts the values by a specified amount.
75.Pp
76The following options are available:
77.Bl -tag -width Ds
78.It Fl A
79Adjust the access and modification time stamps for the file by the
80specified value.
81This flag is intended for use in modifying files with incorrectly set
82time stamps.
83.Pp
84The argument is of the form
85.Dq [-][[hh]mm]SS
86where each pair of letters represents the following:
87.Pp
88.Bl -tag -width Ds -compact -offset indent
89.It Ar -
90Make the adjustment negative: the new time stamp is set to be before
91the old one.
92.It Ar hh
93The number of hours, from 00 to 99.
94.It Ar mm
95The number of minutes, from 00 to 59.
96.It Ar SS
97The number of seconds, from 00 to 59.
98.El
99.Pp
100The
101.Fl A
102flag implies the
103.Fl c
104flag: if any file specified does not exist, it will be silently ignored.
105.It Fl a
106Change the access time of the file.
107The modification time of the file is not changed unless the
108.Fl m
109flag is also specified.
110.It Fl c
111Do not create the file if it does not exist.
112The
113.Nm
114utility does not treat this as an error.
115No error messages are displayed and the exit value is not affected.
116.It Fl d
117Change the access and modification times to the specified date time instead
118of the current time of day.
119The argument is of the form
120.Dq YYYY-MM-DDThh:mm:SS[.frac][tz]
121where the letters represent the following:
122.Bl -tag -width Ds -compact -offset indent
123.It Ar YYYY
124At least four decimal digits representing the year.
125.It Ar MM , Ar DD , Ar hh , Ar mm , Ar SS
126As with
127.Fl t
128time.
129.It Ar T
130The letter
131.Li T
132or a space is the time designator.
133.It Ar .frac
134An optional fraction, consisting of a period or a comma followed by one or
135more digits.
136The number of significant digits depends on the kernel configuration and the
137filesystem, and may be zero.
138.It Ar tz
139An optional letter
140.Li Z
141indicating the time is in
142.Tn UTC .
143Otherwise, the time is assumed to be in local time.
144Local time is affected by the value of the
145.Ev TZ
146environment variable.
147.El
148.It Fl h
149If the file is a symbolic link, change the times of the link
150itself rather than the file that the link points to.
151Note that
152.Fl h
153implies
154.Fl c
155and thus will not create any new files.
156.It Fl m
157Change the modification time of the file.
158The access time of the file is not changed unless the
159.Fl a
160flag is also specified.
161.It Fl r
162Use the access and modifications times from the specified file
163instead of the current time of day.
164.It Fl t
165Change the access and modification times to the specified time instead
166of the current time of day.
167The argument is of the form
168.Dq [[CC]YY]MMDDhhmm[.SS]
169where each pair of letters represents the following:
170.Pp
171.Bl -tag -width Ds -compact -offset indent
172.It Ar CC
173The first two digits of the year (the century).
174.It Ar YY
175The second two digits of the year.
176If
177.Dq YY
178is specified, but
179.Dq CC
180is not, a value for
181.Dq YY
182between 69 and 99 results in a
183.Dq CC
184value of 19.
185Otherwise, a
186.Dq CC
187value of 20 is used.
188.It Ar MM
189The month of the year, from 01 to 12.
190.It Ar DD
191the day of the month, from 01 to 31.
192.It Ar hh
193The hour of the day, from 00 to 23.
194.It Ar mm
195The minute of the hour, from 00 to 59.
196.It Ar SS
197The second of the minute, from 00 to 60.
198.El
199.Pp
200If the
201.Dq CC
202and
203.Dq YY
204letter pairs are not specified, the values default to the current
205year.
206If the
207.Dq SS
208letter pair is not specified, the value defaults to 0.
209.El
210.Sh EXIT STATUS
211.Ex -std
212.Sh COMPATIBILITY
213The obsolescent form of
214.Nm ,
215where a time format is specified as the first argument, is supported.
216When no
217.Fl r
218or
219.Fl t
220option is specified, there are at least two arguments, and the first
221argument is a string of digits either eight or ten characters in length,
222the first argument is interpreted as a time specification of the form
223.Dq MMDDhhmm[YY] .
224.Pp
225The
226.Dq MM ,
227.Dq DD ,
228.Dq hh
229and
230.Dq mm
231letter pairs are treated as their counterparts specified to the
232.Fl t
233option.
234If the
235.Dq YY
236letter pair is in the range 39 to 99, the year is set to 1939 to 1999,
237otherwise, the year is set in the 21st century.
238.Sh SEE ALSO
239.Xr utimensat 2
240.Sh STANDARDS
241The
242.Nm
243utility is expected to be a superset of the
244.St -p1003.2
245specification.
246.Sh HISTORY
247A
248.Nm
249utility appeared in
250.At v7 .
251