1/* Change a port cell to a directory by looking up a name.
2 Copyright (C) 1999-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include <unistd.h>
21#include <hurd.h>
22#include <hurd/port.h>
23#include <hurd/fd.h>
24#include <fcntl.h>
25#include <string.h>
26
27int
28_hurd_change_directory_port_from_name (struct hurd_port *portcell,
29 const char *name)
30{
31 size_t len;
32 const char *lookup;
33 file_t dir;
34
35 /* Append trailing "/." to directory name to force ENOTDIR if it's not a
36 directory and EACCES if we don't have search permission. */
37 len = strlen (s: name);
38 if (len >= 2 && name[len - 2] == '/' && name[len - 1] == '.')
39 lookup = name;
40 else if (len == 0)
41 /* Special-case empty file name according to POSIX. */
42 return __hurd_fail (ENOENT);
43 else
44 {
45 char *n = alloca (len + 3);
46 memcpy (dest: n, src: name, n: len);
47 n[len] = '/';
48 n[len + 1] = '.';
49 n[len + 2] = '\0';
50 lookup = n;
51 }
52
53 dir = __file_name_lookup (lookup, 0, 0);
54 if (dir == MACH_PORT_NULL)
55 return -1;
56
57 _hurd_port_set (portcell, dir);
58 return 0;
59}
60

source code of glibc/hurd/hurdchdir.c