Man Utime en anglais
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 {
               time_t actime;       /* access time */
               time_t 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 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 file system.

 

CONFORMING TO


       utime(): SVr4, POSIX.1-2001.
       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.

       POSIX.1-2001 marks utimes() legacy, which is strange since it  provides
       more functionality than utime().

 

SEE ALSO


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

 

COLOPHON


       This page is part of release 3.05 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                             2008-06-19                          UTIME(2)