glibc/hurd/fd-read.c

/* Copyright (C) 1993, 1994, 1995 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <errno.h>
#include <unistd.h>
#include <hurd.h>
#include <hurd/fd.h>
#include <string.h>

error_t
_hurd_fd_read (struct hurd_fd *fd, void *buf, size_t *nbytes)
{
  error_t err;
  char *data;
  mach_msg_type_number_t nread;

  error_t readfd (io_t port)
    {
      return __io_read (port, &data, &nread, -1, *nbytes);
    }

  data = buf;
  if (err = HURD_FD_PORT_USE (fd, _hurd_ctty_input (port, ctty, readfd)))
    return err;

  if (data != buf)
    {
      memcpy (buf, data, nread);
      __vm_deallocate (__mach_task_self (), (vm_address_t) data, nread);
    }

  *nbytes = nread;
  return 0;
}