touch - change file access and modification times
touch [-acfm] [-r file] [-t [[CC]YY]MMDDhhmm[.SS]] file
The touch utility sets the modification and access times of
files to the
current time of day. If the file doesn't exist, it is created with default
The options are as follows:
-a Change the access time of the file. The modification time of the
file is not changed unless the -m flag is also specified.
-c Do not create the file if it does not exist. The
does not treat this as an error. No error messages
and the exit value is not affected.
-f Attempt to force the update, even if the file permissions do not
currently permit it.
-m Change the modification time of the file. The access time of the
file is not changed unless the -a flag is also specified.
-r Use the access and modification times from the specified file instead
of the current time of day.
-t Change the access and modification times to the
The argument should be in the form ``[[CC]YY]MMDDhhmm[.SS]''
where each pair of letters represents the following:
CC The first two digits of the year (the
YY The second two digits of the year. If
specified, but ``CC'' is not, a value
between 69 and 99 results in a ``CC''
value of 19.
Otherwise, a ``CC'' value of 20 is
MM The month of the year, from 1 to 12.
DD The day of the month, from 1 to 31.
hh The hour of the day, from 0 to 23.
mm The minute of the hour, from 0 to 59.
SS The second of the minute, from 0 to
If the ``CC'' and ``YY'' letter pairs are not specified, the values
default to the current year. If the ``SS'' letter pair is
not specified, the value defaults to 0.
The touch utility exits 0 on success or >0 if an error occurred.
The obsolescent form of touch, where a time format is specified as the
first argument, is supported. When no -r or -t option is
there are at least two arguments, and the first argument is
a string of
digits either eight or ten characters in length, the first
interpreted as a time specification of the form ``MMDDhhmm[YY]''.
The ``MM'', ``DD'', ``hh'' and ``mm'' letter pairs are
treated as their
counterparts specified to the -t option. If the ``YY'' letter pair is in
the range 69 to 99, the year is set from 1969 to 1999; otherwise, the
year is set in the 21st century.
The touch utility is expected to be a superset of the IEEE
A touch utility appeared in Version 7 AT&T UNIX.
OpenBSD 3.6 April 28, 1995
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