/* Change a port cell to a directory by looking up a name.

   Copyright (C) 1999-2018 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 <hurd.h>

#include <hurd/port.h>

#include <hurd/fd.h>

#include <fcntl.h>

#include <string.h>

int

_hurd_change_directory_port_from_name (struct hurd_port *portcell,

				       const char *name)

{

  size_t len;

  const char *lookup;

  file_t dir;

  /* Append trailing "/." to directory name to force ENOTDIR if it's not a

     directory and EACCES if we don't have search permission.  */

  len = strlen (name);

  if (len >= 2 && name[len - 2] == '/' && name[len - 1] == '.')

    lookup = name;

  else if (len == 0)

    /* Special-case empty file name according to POSIX.  */

    return __hurd_fail (ENOENT);

  else

    {

      char *n = alloca (len + 3);

      memcpy (n, name, len);

      n[len] = '/';

      n[len + 1] = '.';

      n[len + 2] = '\0';

      lookup = n;

    }

  dir = __file_name_lookup (lookup, 0, 0);

  if (dir == MACH_PORT_NULL)

    return -1;

  _hurd_port_set (portcell, dir);

  return 0;

}