UTIME(2) Linux Programmer's Manual UTIME(2)

NAME
       utime, utimes - change file last access and modification times

SYNOPSIS
       #include 
       #include 

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

       #include 

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

DESCRIPTION
       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 appropri‐
       ate  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 {
               timet actime;       /* access time */
               timet modtime;      /* modification time */
           };

       The utime() system call allows specification of timestamps with a reso‐
       lution 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 speci‐
       fying timestamps.  The timeval structure is:

           struct timeval {
               long tvsec;        /* seconds */
               long tvusec;       /* 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 pathresolution(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 CAPDACOVERRIDE or the CAPFOWNER 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 CAPFOWNER capability).

       EROFS  path resides on a read-only file system.

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.

       In libc4 and libc5, utimes() is just a wrapper for  utime()  and  hence
       does not allow a subsecond resolution.

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

COLOPHON
       This  page  is  part of release 3.53 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.



Linux                             2008-08-06                          UTIME(2)