glibc/sysdeps/posix/preadv2.c

/* Generic version of preadv2.
   Copyright (C) 2017-2019 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <errno.h>
#include <unistd.h>
#include <sys/uio.h>

#ifndef __OFF_T_MATCHES_OFF64_T

/* Since we define no flags for preadv2 just route to preadv.  */
ssize_t
preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
	 int flags)
{
  if (flags != 0)
    {
      __set_errno (ENOTSUP);
      return -1;
    }

  if (offset == -1)
    return __readv (fd, vector, count);
  else
    return preadv (fd, vector, count, offset);
}

#endif