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OpenSolaris 2009.06 - man page for touch (opensolaris section 1)

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touch(1)				  User Commands 				 touch(1)

NAME
       touch, settime - change file access and modification times

SYNOPSIS
       touch [-acm] [-r ref_file | -t time] file...

       touch [-acm] [date_time] file...

       settime [-f ref_file] [date_time] file...

DESCRIPTION
       The touch utility sets the access and modification times of each file. The file operand is
       created if it does not already exist.

       The time used can be specified by -t time, by the corresponding time fields  of	the  file
       referenced  by  -r  ref_file, or by the date_time operand. If none of these are specified,
       touch uses the current time (the value returned by the time(2) function).

       If neither the -a nor -m options are specified, touch updates both  the	modification  and
       access times.

       A  user with write access to a file, but who is not the owner of the file or a super-user,
       can change the modification and access times of	that  file  only  to  the  current  time.
       Attempts to set a specific time with touch will result in an error.

       The settime utility is equivalent to touch -c [date_time] file.

OPTIONS
       The following options are supported in the touch and settime utilities:

   touch
       The following options are supported for the touch utility:

       -a

	   Changes  the  access  time of file. Does not change the modification time unless -m is
	   also specified.

       -c

	   Does not create a specified file if it does not exist. Does not write  any  diagnostic
	   messages concerning this condition.

       -m

	   Changes  the  modification  time of file. Does not change the access time unless -a is
	   also specified.

       -r ref_file

	   Uses the corresponding times of the file named by  ref_file	instead  of  the  current
	   time.

       -t time

	   Uses  the specified time instead of the current time. time will be a decimal number of
	   the form:

	     [[CC]YY]MMDDhhmm[.SS]

	   where each two digits represent the following:

	   MM

	       The month of the year [01-12].

	   DD

	       The day of the month [01-31].

	   hh

	       The hour of the day [00-23].

	   mm

	       The minute of the hour [00-59].

	   CC

	       The first two digits of the year.

	   YY

	       The second two digits of the year.

	   SS

	       The second of the minute [00-61].

	   Both CC and YY are optional. If neither is given, the current year will be assumed. If
	   YY is specified, but CC is not, CC will be derived as follows:

	   +-----------------------------------------------------------+
	   |	     If YY is:			  CC becomes:	       |
	   +-----------------------------------------------------------+
	   |69-99			  19			       |
	   |00-38			  20			       |
	   |39-68			  ERROR 		       |
	   +-----------------------------------------------------------+
	   The	resulting  time  will be affected by the value of the TZ environment variable. If
	   the resulting time value precedes the Epoch, touch will exit immediately with an error
	   status. The range of valid times is the Epoch to January 18, 2038.

	   The	range  for SS is [00-61] rather than [00-59] because of leap seconds. If SS is 60
	   or 61, and the resulting time, as affected by the TZ environment  variable,	does  not
	   refer  to  a  leap  second, the resulting time will be one or two seconds after a time
	   where SS is 59. If SS is not given, it is assumed to be 0.

   settime
       The following option is supported for the settime utility:

       -f ref_file

	   Uses the corresponding times of the file named by  ref_file	instead  of  the  current
	   time.

OPERANDS
       The following operands are supported for the touch and settime utilities:

       file

	   A path name of a file whose times are to be modified.

       date_time

	   Uses  the  specified  date_time instead of the current time. This operand is a decimal
	   number of the form:

	     MMDDhhmm[YY]

	   where each two digits represent the following:

	   MM

	       The month of the year [01-12].

	   DD

	       The day of the month [01-31].

	   hh

	       The hour of the day [00-23].

	   mm

	       The minute of the hour [00-59].

	   YY

	       The second two digits of the year.

	       YY is optional. If it is omitted, the current year will be assumed. If YY is spec-
	       ified, the year will be derived as follows:

	   +-----------------------------------------------------------+
	   |		YY		       Corresponding Year      |
	   |69-99			  1969-1999		       |
	   |00-38			  2000-2038		       |
	   |39-68			  ERROR 		       |
	   +-----------------------------------------------------------+
	   If  no  -r  option  is specified, no -t option is specified, at least two operands are
	   specified, and the first operand is an eight- or ten-digit decimal integer, the  first
	   operand  will  be assumed to be a date_time operand. Otherwise, the first operand will
	   be assumed to be a file operand.

USAGE
       See largefile(5) for the description of the behavior  of  touch	when  encountering  files
       greater than or equal to 2 Gbyte ( 2^31 bytes).

       When existing file access and modification times cannot be determined (which will occur if
       a call to stat(2) fails), both times can  be  changed  to  known  values  by  settime  and
       utime(2). However, in this case, touch -a (without -m) and touch -m (without -a) will fail
       because the unchanged time cannot be preserved.

ENVIRONMENT VARIABLES
       See environ(5) for descriptions of the following environment  variables	that  affect  the
       execution of touch: LANG, LC_ALL, LANG, LC_ALL, LC_CTYPE, LC_MESSAGES, and NLSPATH.

       TZ

	   Determine  the  timezone  to  be used for interpreting the time option-argument or the
	   date_time operand.

EXIT STATUS
       The following exit values are returned:

       0

	   The touch utility executed successfully and all requested changes were made.

       >0

	   An error occurred.  The touch utility returned the number of files for which the times
	   could not be successfully modified.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+
       |CSI			     |Enabled			   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Committed 		   |
       +-----------------------------+-----------------------------+
       |Standard		     |See standards(5). 	   |
       +-----------------------------+-----------------------------+

SEE ALSO
       stat(2), time(2), utime(2), attributes(5), environ(5), largefile(5), standards(5)

NOTES
       Users  familiar	with  the  BSD	environment  will find that for the touch utility, the -f
       option is accepted but ignored. The -f option is unnecessary because  touch  will  succeed
       for all files owned by the user regardless of the permissions on the files.

SunOS 5.11				    9 Sep 2008					 touch(1)
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