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utime(2)                      System Calls Manual                     utime(2)

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

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <utime.h>

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

       #include <sys/time.h>

       int utimes(const char *filename,
                 const struct timeval times[_Nullable 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.  The status change time (ctime) will be set to  the
       current time, even if the other time stamps don't actually change.

       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 to indicate the error.

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 ei-
              ther 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.

STANDARDS
       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), inode(7)

Linux man-pages 6.03              2022-12-03                          utime(2)

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