path: root/usr.bin/touch/touch.1

.\"	$OpenBSD: touch.1,v 1.18 2011/08/20 06:44:24 guenther Exp $
.\"	$NetBSD: touch.1,v 1.8 1995/08/31 22:10:05 jtc Exp $
.\"
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.\"     @(#)touch.1	8.3 (Berkeley) 4/28/95
.\"
.Dd $Mdocdate: August 20 2011 $
.Dt TOUCH 1
.Os
.Sh NAME
.Nm touch
.Nd change file access and modification times
.Sh SYNOPSIS
.Nm touch
.Op Fl acm
.Op Fl d Ar YYYY-MM-DDThh:mm:SS[.frac][Z]
.Op Fl r Ar file
.Op Fl t Ar [[CC]YY]MMDDhhmm[.SS]
.Ar
.Sh DESCRIPTION
The
.Nm
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 permissions.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl a
Change the access time of the file.
The modification time of the file is not changed unless the
.Fl m
flag is also specified.
.It Fl c
Do not create the file if it does not exist.
The
.Nm
utility does not treat this as an error.
No error messages are displayed and the exit value is not affected.
.It Fl d Ar YYYY-MM-DDThh:mm:SS[.frac][Z]
Change the access and modification times to the specified time.
The argument should be in the form
.Dq YYYY-MM-DDThh:mm:SS[.frac][Z]
where the parts of the argument represent the following:
.Pp
.Bl -tag -width .frac -compact -offset indent
.It Ar YYYY
The four digits of the year.
.It Ar MM
The month of the year, from 1 to 12.
.It Ar DD
The day of the month, from 1 to 31.
.It Ar T
Either the capital letter
.Sq T
or a single space.
.It Ar hh
The hour of the day, from 0 to 23.
.It Ar mm
The minute of the hour, from 0 to 59.
.It Ar SS
The second of the minute, from 0 to 60.
.It Ar .frac
The decimal fraction of the second, either a period or comma, followed
by one or more decimal digits.
.It Ar Z
The timezone specifier, a capital letter
.Sq Z
indicating that the time is in UTC.
If not specified, the time is in the local timezone.
.El
.It Fl m
Change the modification time of the file.
The access time of the file is not changed unless the
.Fl a
flag is also specified.
.It Fl r Ar file
Use the access and modification times from the specified file
instead of the current time of day.
.It Fl t Ar [[CC]YY]MMDDhhmm[.SS]
Change the access and modification times to the specified time.
The argument should be in the form
.Dq [[CC]YY]MMDDhhmm[.SS]
where each pair of letters represents the following:
.Pp
.Bl -tag -width Ds -compact -offset indent
.It Ar CC
The first two digits of the year (the century).
.It Ar YY
The second two digits of the year.
If
.Dq YY
is specified, but
.Dq CC
is not, a value for
.Dq YY
between 69 and 99 results in a
.Dq CC
value of 19.
Otherwise, a
.Dq CC
value of 20 is used.
.It Ar MM
The month of the year, from 1 to 12.
.It Ar DD
The day of the month, from 1 to 31.
.It Ar hh
The hour of the day, from 0 to 23.
.It Ar mm
The minute of the hour, from 0 to 59.
.It Ar SS
The second of the minute, from 0 to 60.
.El
.Pp
If the
.Dq CC
and
.Dq YY
letter pairs are not specified, the values default to the current
year.
If the
.Dq SS
letter pair is not specified, the value defaults to 0.
.El
.Sh EXIT STATUS
.Ex -std touch
.Sh SEE ALSO
.Xr utimes 2
.Sh STANDARDS
The
.Nm
utility is compliant with the
.St -p1003.1-2008
specification.
.Pp
The obsolescent form of
.Nm touch ,
where a time format is specified as the first argument, is supported.
When no
.Fl r
or
.Fl t
option is specified, there are at least two arguments, and the first
argument is a string of digits either eight or ten characters in length,
the first argument is interpreted as a time specification of the form
.Dq MMDDhhmm[YY] .
.Pp
The
.Dq MM ,
.Dq DD ,
.Dq hh
and
.Dq mm
letter pairs are treated as their counterparts specified to the
.Fl t
option.
If the
.Dq 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.
.Sh HISTORY
A
.Nm
utility appeared in
.At v7 .