--- /dev/null
+.\" $NetBSD: utimes.2,v 1.13 1999/03/22 19:45:11 garbled Exp $
+.\"
+.\" Copyright (c) 1990, 1993
+.\" The Regents of the University of California. All rights reserved.
+.\" Copyright (c) 2012, Jilles Tjoelker
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\" 3. Neither the name of the University nor the names of its contributors
+.\" may be used to endorse or promote products derived from this software
+.\" without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" @(#)utimes.2 8.1 (Berkeley) 6/4/93
+.\" $FreeBSD$
+.\"
+.Dd January 17, 2016
+.Dt UTIMENSAT 2
+.Os
+.Sh NAME
+.Nm futimens ,
+.Nm utimensat
+.Nd set file access and modification times
+.Sh SYNOPSIS
+.In sys/stat.h
+.Ft int
+.Fn futimens "int fd" "const struct timespec times[2]"
+.Ft int
+.Fo utimensat
+.Fa "int fd"
+.Fa "const char *path"
+.Fa "const struct timespec times[2]"
+.Fa "int flag"
+.Fc
+.Sh DESCRIPTION
+The access and modification times of the file named by
+.Fa path
+or referenced by
+.Fa fd
+are changed as specified by the argument
+.Fa times .
+The inode-change-time of the file is set to the current time.
+.Pp
+If
+.Fa path
+specifies a relative path,
+it is relative to the current working directory if
+.Fa fd
+is
+.Dv AT_FDCWD
+and otherwise relative to the directory associated with the file descriptor
+.Fa fd .
+.Pp
+The
+.Va tv_nsec
+field of a
+.Vt timespec
+structure
+can be set to the special value
+.Dv UTIME_NOW
+to set the current time, or to
+.Dv UTIME_OMIT
+to leave the time unchanged.
+In either case, the
+.Va tv_sec
+field is ignored.
+.Pp
+If
+.Fa times
+is
+.No non- Ns Dv NULL ,
+it is assumed to point to an array of two timespec 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.
+If
+.Fa times
+is
+.Dv NULL ,
+this is equivalent to passing
+a pointer to an array of two timespec structures
+with both
+.Va tv_nsec
+fields set to
+.Dv UTIME_NOW .
+.Pp
+If both
+.Va tv_nsec
+fields are
+.Dv UTIME_OMIT ,
+the timestamps remain unchanged and
+no permissions are needed for the file itself,
+although search permissions may be required for the path prefix.
+The call may or may not succeed if the named file does not exist.
+.Pp
+If both
+.Va tv_nsec
+fields are
+.Dv UTIME_NOW ,
+the caller must be the owner of the file, have permission to
+write the file, or be the super-user.
+.Pp
+For all other values of the timestamps,
+the caller must be the owner of the file or be the super-user.
+.Pp
+The values for the
+.Fa flag
+argument of the
+.Fn utimensat
+system call
+are constructed by a bitwise-inclusive OR of flags from the following list,
+defined in
+.In fcntl.h :
+.Bl -tag -width indent
+.It Dv AT_SYMLINK_NOFOLLOW
+If
+.Fa path
+names a symbolic link, the symbolic link's times are changed.
+By default,
+.Fn utimensat
+changes the times of the file referenced by the symbolic link.
+.El
+.Sh RETURN VALUES
+.Rv -std
+.Sh ERRORS
+These system calls will fail if:
+.Bl -tag -width Er
+.It Bq Er EACCES
+The
+.Fa times
+argument is
+.Dv NULL ,
+or both
+.Va tv_nsec
+values are
+.Dv UTIME_NOW ,
+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.
+.It Bq Er EINVAL
+The
+.Va tv_nsec
+component of at least one of the values specified by the
+.Fa times
+argument has a value less than 0 or greater than 999999999 and is not equal to
+.Dv UTIME_NOW
+or
+.Dv UTIME_OMIT .
+.It Bq Er EIO
+An I/O error occurred while reading or writing the affected inode.
+.It Bq Er EPERM
+The
+.Fa times
+argument is not
+.Dv NULL
+nor are both
+.Va tv_nsec
+values
+.Dv UTIME_NOW ,
+nor are both
+.Va tv_nsec
+values
+.Dv UTIME_OMIT
+and the calling process's effective user ID
+does not match the owner of the file and is not the super-user.
+.It Bq Er EPERM
+The named file has its immutable or append-only flag set, see the
+.Xr chflags 2
+manual page for more information.
+.It Bq Er EROFS
+The file system containing the file is mounted read-only.
+.El
+.Pp
+The
+.Fn futimens
+system call
+will fail if:
+.Bl -tag -width Er
+.It Bq Er EBADF
+The
+.Fa fd
+argument
+does not refer to a valid descriptor.
+.El
+.Pp
+The
+.Fn utimensat
+system call
+will fail if:
+.Bl -tag -width Er
+.It Bq Er EACCES
+Search permission is denied for a component of the path prefix.
+.It Bq Er EBADF
+The
+.Fa path
+argument does not specify an absolute path and the
+.Fa fd
+argument is neither
+.Dv AT_FDCWD
+nor a valid file descriptor.
+.It Bq Er EFAULT
+The
+.Fa path
+argument
+points outside the process's allocated address space.
+.It Bq Er ELOOP
+Too many symbolic links were encountered in translating the pathname.
+.It Bq Er ENAMETOOLONG
+A component of a pathname exceeded
+.Dv NAME_MAX
+characters, or an entire path name exceeded
+.Dv PATH_MAX
+characters.
+.It Bq Er ENOENT
+The named file does not exist.
+.It Bq Er ENOTDIR
+A component of the path prefix is not a directory.
+.It Bq Er ENOTDIR
+The
+.Fa path
+argument is not an absolute path and
+.Fa fd
+is neither
+.Dv AT_FDCWD
+nor a file descriptor associated with a directory.
+.El
+.Sh SEE ALSO
+.Xr chflags 2 ,
+.Xr stat 2 ,
+.Xr symlink 2 ,
+.Xr utimes 2 ,
+.Xr utime 3 ,
+.Xr symlink 7
+.Sh STANDARDS
+The
+.Fn futimens
+and
+.Fn utimensat
+system calls are expected to conform to
+.St -p1003.1-2008 .