touch(1)

NAME
     touch - update access and modification times of a file

SYNOPSIS
     touch [ -amc ] [ mmddhhmm[yy] ] files

     touch [ -amc ] [ -r ref_file | -t [[cc]yy]mmddhhmm[.ss] ] files

DESCRIPTION
     touch causes the access and modification times of each argument to be
     updated.  The file name is created if it does not exist.  If no time is
     specified [see date(1)] the current time is used.  The -a and -m options
     cause touch to update only the access or modification times respectively
     (default is -am).  The -c option silently prevents touch from creating
     the file if it did not previously exist.  The -r option causes touch to
     use the modification time of the file named by the pathname ref_file
     instead of of the current time.

     The -t [[cc]yy]mmddhhmm[.ss] option specifies to the time to use instead
     of the current time.  The option-argument will be a decimal number where
     each two digits represents 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 (century).

          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: 69-99 then cc becomes 19.

               If yy is: 00-68 then cc becomes 20.

          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 a value, it is assumed to be zero.
     The return code from touch is the number of files for which the times
     could not be successfully modified (including files that did not exist
     and were not created).

FILES
     /usr/lib/locale/locale/LC_MESSAGES/uxcore.abi
          language-specific message file [See LANG on environ (5).]

SEE ALSO
     date(1), utime(2)

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

     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
     specification of the form mmddhhmm[yy].  Otherwise, the first operand
     will be assumed to be a file name.