Description

   The utime function sets the access and modification times of the
   filenamed by the path argument. The file must be openable for
   write-access to use this function.

   If times is a NULL pointer, the access and modification times of
   the file are set to the current time. To use utime in this way,
   the effective user ID of the process must match the owner of the
   file, or the process must have write permission to the file or
   have appropriate privileges.

   If times is not a NULL pointer, it is interpreted as a pointer
   to a utimbuf structure, and the access and modification times
   are set to the values in the specified structure. Only a process
   with an effective user ID equal to the user ID of the file or a
   process with appropriate privileges can use utime this way.

   The utimbuf structure is defined by the <utime.h> header. The
   times in the utimbuf structure are measured in seconds since the
   Epoch.

   Upon successful completion, utime marks the time of the last file
   status change, st_ctime, to be updated. See the <stat.h> header
   file.

                    NOTE (Integrity servers, Alpha)

      On OpenVMS Alpha and Integrity server systems, the stat,
      fstat, utime, and utimes functions have been enhanced to
      take advantage of the new file-system support for POSIX
      compliant file timestamps.

      This support is available only on ODS-5 devices on OpenVMS
      Alpha systems beginning with a version of OpenVMS Alpha
      after Version 7.3.

      Before this change, stat and fstat set the values of the st_
      ctime, st_mtime, and st_atime fields based on the following
      file attributes:

         st_ctime - ATR$C_CREDATE (file creation time)
         st_mtime - ATR$C_REVDATE (file revision time)
         st_atime - was always set to st_mtime because no support
         for file access time was available

      Also, for the file-modification time, utime and utimes were
      modifying the ATR$C_REVDATE file attribute, and ignoring the
      file-access-time argument.

      After the change, for a file on an ODS-5 device, the stat
      and fstat functions set the values of the st_ctime, st_
      mtime, and st_atime fields based on the following new file
      attributes:

         st_ctime - ATR$C_ATTDATE (last attribute modification
         time)
         st_mtime - ATR$C_MODDATE (last data modification time)
         st_atime - ATR$C_ACCDATE (last access time)

      If ATR$C_ACCDATE is 0, as on an ODS-2 device, the stat and
      fstat functions set st_atime to st_mtime.

      For the file-modification time, the utime and utimes
      functions modify both the ATR$C_REVDATE and ATR$C_MODDATE
      file attributes. For the file-access time, these functions
      modify the ATR$C_ACCDATE file attribute. Setting the ATR$C_
      MODDATE and ATR$C_ACCDATE file attributes on an ODS-2 device
      has no effect.

      For compatibility, the old behavior of stat, fstat, utime,
      and utimes remains the default, regardless of the kind of
      device.

      The new behavior must be explicitly enabled by defining the
      DECC$EFS_FILE_TIMESTAMPS logical name to "ENABLE" before
      invoking the application. Setting this logical does not
      affect the behavior of stat, fstat, utime, and utimes for
      files on an ODS-2 device.