$ touch [option] [file]
-a : アクセス時刻を変更する
-d : 現在時刻を変更する
-m : 更新日時を変更する
-t : 指定日時に変更する
$ toucht hoge.txt
# 「hoge.txt」ファイルのタイムスタンプを指定日時に変更する(2000.1.1 0:0)
$ touch -t 200001010000 hoge.txt
$ touch hoge
The touch utility sets the modification and access times of files. If any file does not
exist, it is created with default permissions.
By default, touch changes both modification and access times. The -a and -m flags may
be used to select the access time or the modification time individually. Selecting both
is equivalent to the default. By default, the timestamps are set to the current time.
The -t flag explicitly specifies a different time, and the -r flag specifies to set the
times those of the specified file. The -A flag adjusts the values by a specified
The following options are available:
-A Adjust the access and modification time stamps for the file by the specified
value. This flag is intended for use in modifying files with incorrectly set
The argument is of the form ``[-][[hh]mm]SS'' where each pair of letters repre-
sents the following:
- Make the adjustment negative: the new time stamp is set to be
before the old one.
hh The number of hours, from 00 to 99.
mm The number of minutes, from 00 to 59.
SS The number of seconds, from 00 to 59.
The -A flag implies the -c flag: if any file specified does not exist, it will
be silently ignored.
-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 touch utility does not treat
this as an error. No error messages are displayed and the exit value is not
-f Attempt to force the update, even if the file permissions do not currently per-
-h If the file is a symbolic link, change the times of the link itself rather than
the file that the link points to. Note that -h implies -c and thus will not
create any new files.
-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 modifications times from the specified file instead of the
current time of day.
-t Change the access and modification times to the specified time instead of the
current time of day. The argument is of the form ``[[CC]YY]MMDDhhmm[.SS]''
where each pair of letters represents the following:
CC The first two digits of the year (the century).
YY The second two digits of the year. If ``YY'' is specified, but
``CC'' is not, a value for ``YY'' between 69 and 99 results in a
``CC'' value of 19. Otherwise, a ``CC'' value of 20 is used.
MM The month of the year, from 01 to 12.
DD the day of the month, from 01 to 31.
hh The hour of the day, from 00 to 23.
mm The minute of the hour, from 00 to 59.
SS The second of the minute, from 00 to 61.
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.