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31 .\" @(#)touch.1 8.3 (Berkeley) 4/28/95
38 .Nd change file access and modification times
41 .Op Fl A Ar [-][[hh]mm]SS
44 .Op Fl t Ar [[CC]YY]MMDDhhmm[.SS]
45 .Op Fl d Ar YYYY-MM-DDThh:mm:SS[.frac][tz]
50 utility sets the modification and access times of files.
51 If any file does not exist, it is created with default permissions.
55 changes both modification and access times.
60 flags may be used to select the access time or the modification time
62 Selecting both is equivalent to the default.
63 By default, the timestamps are set to the current time.
68 flags explicitly specify a different time, and the
70 flag specifies to set the times those of the specified file.
73 flag adjusts the values by a specified amount.
75 The following options are available:
78 Adjust the access and modification time stamps for the file by the
80 This flag is intended for use in modifying files with incorrectly set
83 The argument is of the form
85 where each pair of letters represents the following:
87 .Bl -tag -width Ds -compact -offset indent
89 Make the adjustment negative: the new time stamp is set to be before
92 The number of hours, from 00 to 99.
94 The number of minutes, from 00 to 59.
96 The number of seconds, from 00 to 59.
103 flag: if any file specified does not exist, it will be silently ignored.
105 Change the access time of the file.
106 The modification time of the file is not changed unless the
108 flag is also specified.
110 Do not create the file if it does not exist.
113 utility does not treat this as an error.
114 No error messages are displayed and the exit value is not affected.
116 Change the access and modification times to the specified date time instead
117 of the current time of day.
118 The argument is of the form
119 .Dq YYYY-MM-DDThh:mm:SS[.frac][tz]
120 where the letters represent the following:
121 .Bl -tag -width Ds -compact -offset indent
123 At least four decimal digits representing the year.
124 .It Ar MM , Ar DD , Ar hh , Ar mm , Ar SS
131 or a space is the time designator.
133 An optional fraction, consisting of a period or a comma followed by one or
135 The number of significant digits depends on the kernel configuration and the
136 filesystem, and may be zero.
140 indicating the time is in
142 Otherwise, the time is assumed to be in local time.
143 Local time is affected by the value of the
145 environment variable.
148 If the file is a symbolic link, change the times of the link
149 itself rather than the file that the link points to.
154 and thus will not create any new files.
156 Change the modification time of the file.
157 The access time of the file is not changed unless the
159 flag is also specified.
161 Use the access and modifications times from the specified file
162 instead of the current time of day.
164 Change the access and modification times to the specified time instead
165 of the current time of day.
166 The argument is of the form
167 .Dq [[CC]YY]MMDDhhmm[.SS]
168 where each pair of letters represents the following:
170 .Bl -tag -width Ds -compact -offset indent
172 The first two digits of the year (the century).
174 The second two digits of the year.
181 between 69 and 99 results in a
188 The month of the year, from 01 to 12.
190 the day of the month, from 01 to 31.
192 The hour of the day, from 00 to 23.
194 The minute of the hour, from 00 to 59.
196 The second of the minute, from 00 to 60.
203 letter pairs are not specified, the values default to the current
207 letter pair is not specified, the value defaults to 0.
212 The obsolescent form of
214 where a time format is specified as the first argument, is supported.
219 option is specified, there are at least two arguments, and the first
220 argument is a string of digits either eight or ten characters in length,
221 the first argument is interpreted as a time specification of the form
230 letter pairs are treated as their counterparts specified to the
235 letter pair is in the range 39 to 99, the year is set to 1939 to 1999,
236 otherwise, the year is set in the 21st century.
242 utility is expected to be a superset of the