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UTIMES(2)                     System Calls Manual                    UTIMES(2)

NAME
     utimes, lutimes, futimes, utimens, lutimens, futimens, utimensat - set
     file access and modification times

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/time.h>

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

     int
     lutimes(const char *path, const struct timeval times[2]);

     int
     futimes(int fd, const struct timeval times[2]);

     #include <sys/stat.h>

     int
     utimens(const char *path, const struct timespec times[2]);

     int
     lutimens(const char *path, const struct timespec times[2]);

     int
     futimens(int fd, const struct timespec times[2]);

     #include <sys/stat.h>
     #include <fcntl.h>

     int
     utimensat(int fd, const char *path, const struct timespec times[2],
         int flag);

DESCRIPTION
     The access and modification times of the file named by path or referenced
     by fd are changed as specified by the argument times.

     If times is NULL, the access and modification times are set to the
     current time.  The caller must be the owner of the file, have permission
     to write the file, or be the super-user.

     If times is non-NULL, it is assumed to point to an array of two timeval
     structures.  The access time is set to the value of the first element,
     and the modification time is set to the value of the second element.  For
     file systems that support file birth (creation) times (such as UFS2), the
     birth time will be set to the value of the second element if the second
     element is older than the currently set birth time.  To set both a birth
     time and a modification time, two calls are required; the first to set
     the birth time and the second to set the (presumably newer) modification
     time.  Ideally a new system call will be added that allows the setting of
     all three times at once.  The caller must be the owner of the file or be
     the super-user.

     In either case, the inode-change-time of the file is set to the current
     time.

     lutimes() is like utimes() except in the case where the named file is a
     symbolic link, in which case lutimes() changes the access and
     modification times of the link, while utimes() changes the times of the
     file the link references.

     utimens(), lutimens(), and futimens() are like utimes(), lutimes(), and
     futimes() respectively except that time is specified with nanosecond
     instead of microsecond precision.

     utimensat() works the same way as utimens() except if path is relative.
     In that case, it is looked up from a directory whose file descriptor was
     passed as fd.  Search permission is required on this directory.  fd can
     be set to AT_FDCWD in order to specify the current directory.

     When it operates on a symbolic link, utimensat() will change the target's
     time unless AT_SYMLINK_NOFOLLOW is set in flag.  In that later case, the
     symbolic link's dates are changed.

     The nanosecond fields for utimens(), lutimens(), futimens(), and
     utimensat() can be set to the special value UTIME_NOW to set the current
     time, or to UTIME_OMIT to let the time unchanged (this allows changing
     access time but not modification time, and vice-versa).

RETURN VALUES
     The utimes(), lutimes(), futimes(), utimens(), lutimens(), futimens(),
     and utimensat() functions return the value 0 if successful; otherwise the
     value -1 is returned and the global variable errno is set to indicate the
     error.

ERRORS
     utimes(), lutimes(), utimens(), lutimens(), and utimensat() will fail if:

     [EACCES]           Search permission is denied for a component of the
                        path prefix; or the times argument is NULL and the
                        effective user ID of the process does not match the
                        owner of the file, and is not the super-user, and
                        write access is denied.

     [EFAULT]           path or times points outside the process's allocated
                        address space.

     [EIO]              An I/O error occurred while reading or writing the
                        affected inode.

     [ELOOP]            Too many symbolic links were encountered in
                        translating the pathname.

     [ENAMETOOLONG]     A component of a pathname exceeded {NAME_MAX}
                        characters, or an entire path name exceeded {PATH_MAX}
                        characters.

     [ENOENT]           The named file does not exist.

     [ENOTDIR]          A component of the path prefix is not a directory.

     [EPERM]            The times argument is not NULL and the calling
                        process's effective user ID does not match the owner
                        of the file and is not the super-user.

     [EROFS]            The file system containing the file is mounted read-
                        only.

     In addition, utimensat() will fail if:

     [EBADF]            path does not specify an absolute path and fd is
                        neither AT_FDCWD nor a valid file descriptor open for
                        reading or searching.

     [ENOTDIR]          path is not an absolute path and fd is a file
                        descriptor associated with a non-directory file.

     futimes() and futimens() will fail if:

     [EACCES]           The times argument is NULL and the effective user ID
                        of the process does not match the owner of the file,
                        and is not the super-user, and write access is denied.

     [EBADF]            fd does not refer to a valid descriptor.

     [EFAULT]           times points outside the process's allocated address
                        space.

     [EIO]              An I/O error occurred while reading or writing the
                        affected inode.

     [EPERM]            The times argument is not NULL and the calling
                        process's effective user ID does not match the owner
                        of the file and is not the super-user.

     [EROFS]            The file system containing the file is mounted read-
                        only.

SEE ALSO
     stat(2), utime(3), symlink(7)

STANDARDS
     The utimes() function conforms to IEEE Std 1003.1-2001 ("POSIX.1").  It
     was however marked as legacy in the IEEE Std 1003.1-2004 ("POSIX.1")
     revision.  futimens() and utimensat() functions conform to IEEE Std
     1003.1-2008 ("POSIX.1").

HISTORY
     The utimes() function call appeared in 4.2BSD.  The futimes() function
     call appeared in NetBSD 1.2.  The lutimes() function call appeared in
     NetBSD 1.3.  Birthtime setting support was added in NetBSD 5.0.
     futimens() and utimensat() functions calls appeared in NetBSD 6.0.

NetBSD 10.99                  September 14, 2013                  NetBSD 10.99