1 /* Test duplicating file descriptors.
2 Copyright (C) 2009-2011 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* Written by Eric Blake <ebb9@byu.net>, 2009,
18 and Bruno Haible <bruno@clisp.org>, 2009. */
24 #include "signature.h"
25 SIGNATURE_CHECK (dup3, int, (int, int, int));
31 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
32 /* Get declarations of the Win32 API functions. */
33 # define WIN32_LEAN_AND_MEAN
35 /* Get _get_osfhandle. */
36 # include "msvc-nothrow.h"
39 #include "binary-io.h"
42 /* Return true if FD is open. */
46 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
47 /* On Win32, the initial state of unassigned standard file
48 descriptors is that they are open but point to an
49 INVALID_HANDLE_VALUE, and there is no fcntl. */
50 return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
53 # error Please port fcntl to your platform
55 return 0 <= fcntl (fd, F_GETFL);
59 /* Return true if FD is not inherited to child processes. */
63 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
64 HANDLE h = (HANDLE) _get_osfhandle (fd);
66 ASSERT (GetHandleInformation (h, &flags));
67 return (flags & HANDLE_FLAG_INHERIT) == 0;
70 ASSERT ((flags = fcntl (fd, F_GETFD)) >= 0);
71 return (flags & FD_CLOEXEC) != 0;
81 for (use_cloexec = 0; use_cloexec <= 1; use_cloexec++)
86 const char *file = "test-dup3.tmp";
87 int fd = open (file, O_CREAT | O_TRUNC | O_RDWR, 0600);
97 /* Assume std descriptors were provided by invoker. */
98 ASSERT (STDERR_FILENO < fd);
99 ASSERT (is_open (fd));
100 /* Ignore any other fd's leaked into this process. */
103 ASSERT (!is_open (fd + 1));
104 ASSERT (!is_open (fd + 2));
106 /* Assigning to self is invalid. */
108 ASSERT (dup3 (fd, fd, o_flags) == -1);
109 ASSERT (errno == EINVAL);
110 ASSERT (is_open (fd));
112 /* If the source is not open, then the destination is unaffected. */
114 ASSERT (dup3 (fd + 1, fd + 2, o_flags) == -1);
115 ASSERT (errno == EBADF);
116 ASSERT (!is_open (fd + 2));
118 ASSERT (dup3 (fd + 1, fd, o_flags) == -1);
119 ASSERT (errno == EBADF);
120 ASSERT (is_open (fd));
122 /* The destination must be valid. */
124 ASSERT (dup3 (fd, -2, o_flags) == -1);
125 ASSERT (errno == EBADF);
127 ASSERT (dup3 (fd, 10000000, o_flags) == -1);
128 ASSERT (errno == EBADF);
130 /* Using dup3 can skip fds. */
131 ASSERT (dup3 (fd, fd + 2, o_flags) == fd + 2);
132 ASSERT (is_open (fd));
133 ASSERT (!is_open (fd + 1));
134 ASSERT (is_open (fd + 2));
136 ASSERT (is_cloexec (fd + 2));
138 ASSERT (!is_cloexec (fd + 2));
140 /* Verify that dup3 closes the previous occupant of a fd. */
141 ASSERT (open ("/dev/null", O_WRONLY, 0600) == fd + 1);
142 ASSERT (dup3 (fd + 1, fd, o_flags) == fd);
143 ASSERT (close (fd + 1) == 0);
144 ASSERT (write (fd, "1", 1) == 1);
145 ASSERT (dup3 (fd + 2, fd, o_flags) == fd);
146 ASSERT (lseek (fd, 0, SEEK_END) == 0);
147 ASSERT (write (fd + 2, "2", 1) == 1);
148 ASSERT (lseek (fd, 0, SEEK_SET) == 0);
149 ASSERT (read (fd, buffer, 1) == 1);
150 ASSERT (*buffer == '2');
153 ASSERT (close (fd + 2) == 0);
154 ASSERT (close (fd) == 0);
155 ASSERT (unlink (file) == 0);