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TOUCH (1)

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touch - update file access and modification times

CONTENTS

Synopsis
Description
See Also

touch [-amc] [MMDDhhmm[YY]] file ...
touch [-amc] [-r ref_file|-t time] file ...

The touch utility changes the access and modification times of files. It creates a file if it does not already exist. If none of the arguments specify the time to set, the current time is used.

If neither the -r nor the -t option is used to specify a time value and the first non-option argument begins with a digit, and it consists of exactly eight or ten digits with /usr/5bin/posix/touch and /usr/5bin/posix2001/touch, the times of the files are set to the given time.

The meaning of fields in time specifications is as follows:

CC      The first two digits of the year.
YY      The second two digits of the year.
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).
SS      The second of the minute (00-61).

Unless YY is present, the current year is used. If YY is given without CC, the century is 19 if YY is in the range of 69-99, or 20 for YY values of 00-68.

The following options are accepted:

-a	Change the access time, but not the modification time unless -m is also present.
-c	If a file does not exist, it is not created. No diagnostic message is printed; for /usr/5bin/touch and /usr/5bin/s42/touch, the exit status is incremented. The exit status is not affected for /usr/5bin/posix/touch and /usr/5bin/posix2001/touch.
-m	Change the access time, but not the modification time unless -a is also present.
The following options have been introduced by POSIX.2:
-r ref_file
	The corresponding time of the specified file is used instead of the current time.
-t time	Instead of the current time, the time specified as [[CC]YY]MMDDhhmm[.SS] is used.

The exit status is the number of files that were not successfully processed.

date(1), utime(2)