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utime(2)


NAME

   utime, utimes - change file last access and modification times

SYNOPSIS

   #include <sys/types.h>
   #include <utime.h>

   int utime(const char *filename, const struct utimbuf *times);

   #include <sys/time.h>

   int utimes(const char *filename, const struct timeval times[2]);

DESCRIPTION

   Note: modern applications may prefer to use the interfaces described in
   utimensat(2).

   The utime() system call changes the access and  modification  times  of
   the  inode  specified  by  filename to the actime and modtime fields of
   times respectively.

   If times is NULL, then the access and modification times  of  the  file
   are set to the current time.

   Changing   timestamps   is  permitted  when:  either  the  process  has
   appropriate privileges, or the effective user ID equals the user ID  of
   the file, or times is NULL and the process has write permission for the
   file.

   The utimbuf structure is:

       struct utimbuf {
           time_t actime;       /* access time */
           time_t modtime;      /* modification time */
       };

   The utime() system call  allows  specification  of  timestamps  with  a
   resolution of 1 second.

   The  utimes()  system call is similar, but the times argument refers to
   an array rather than a structure.   The  elements  of  this  array  are
   timeval  structures,  which  allow  a  precision  of  1 microsecond for
   specifying timestamps.  The timeval structure is:

       struct timeval {
           long tv_sec;        /* seconds */
           long tv_usec;       /* microseconds */
       };

   times[0] specifies the new access time, and times[1] specifies the  new
   modification  time.  If times is NULL, then analogously to utime(), the
   access and modification times of the file are set to the current time.

RETURN VALUE

   On success, zero is returned.  On error, -1 is returned, and  errno  is
   set appropriately.

ERRORS

   EACCES Search  permission  is  denied for one of the directories in the
          path prefix of path (see also path_resolution(7)).

   EACCES times is NULL, the caller's effective user ID does not match the
          owner  of the file, the caller does not have write access to the
          file, and the caller is not privileged  (Linux:  does  not  have
          either the CAP_DAC_OVERRIDE or the CAP_FOWNER capability).

   ENOENT filename does not exist.

   EPERM  times is not NULL, the caller's effective UID does not match the
          owner of the file, and the caller is not privileged (Linux: does
          not have the CAP_FOWNER capability).

   EROFS  path resides on a read-only filesystem.

CONFORMING TO

   utime(): SVr4, POSIX.1-2001.  POSIX.1-2008 marks utime() as obsolete.
   utimes(): 4.3BSD, POSIX.1-2001.

NOTES

   Linux  does  not allow changing the timestamps on an immutable file, or
   setting the timestamps to something other than the current time  on  an
   append-only file.

SEE ALSO

   chattr(1),  touch(1), futimesat(2), stat(2), utimensat(2), futimens(3),
   futimes(3)

COLOPHON

   This page is part of release 4.09 of the Linux  man-pages  project.   A
   description  of  the project, information about reporting bugs, and the
   latest    version    of    this    page,    can     be     found     at
   https://www.kernel.org/doc/man-pages/.



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