1 /* Test duplicating file descriptors.
2 Copyright (C) 2009-2013 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. */
23 #include "signature.h"
24 SIGNATURE_CHECK (dup2, int, (int, int));
29 #include "binary-io.h"
31 #if GNULIB_TEST_CLOEXEC
35 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
36 /* Get declarations of the native Windows API functions. */
37 # define WIN32_LEAN_AND_MEAN
39 /* Get _get_osfhandle. */
40 # include "msvc-nothrow.h"
45 /* Return non-zero if FD is open. */
49 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
50 /* On native Windows, the initial state of unassigned standard file
51 descriptors is that they are open but point to an
52 INVALID_HANDLE_VALUE, and there is no fcntl. */
53 return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
56 # error Please port fcntl to your platform
58 return 0 <= fcntl (fd, F_GETFL);
62 #if GNULIB_TEST_CLOEXEC
63 /* Return non-zero if FD is open and inheritable across exec/spawn. */
65 is_inheritable (int fd)
67 # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
68 /* On native Windows, the initial state of unassigned standard file
69 descriptors is that they are open but point to an
70 INVALID_HANDLE_VALUE, and there is no fcntl. */
71 HANDLE h = (HANDLE) _get_osfhandle (fd);
73 if (h == INVALID_HANDLE_VALUE || GetHandleInformation (h, &flags) == 0)
75 return (flags & HANDLE_FLAG_INHERIT) != 0;
78 # error Please port fcntl to your platform
80 int i = fcntl (fd, F_GETFD);
81 return 0 <= i && (i & FD_CLOEXEC) == 0;
84 #endif /* GNULIB_TEST_CLOEXEC */
87 # define setmode(f,m) zero ()
88 static int zero (void) { return 0; }
91 /* Return non-zero if FD is open in the given MODE, which is either
92 O_TEXT or O_BINARY. */
94 is_mode (int fd, int mode)
96 int value = setmode (fd, O_BINARY);
104 const char *file = "test-dup2.tmp";
106 int fd = open (file, O_CREAT | O_TRUNC | O_RDWR, 0600);
108 /* Assume std descriptors were provided by invoker. */
109 ASSERT (STDERR_FILENO < fd);
110 ASSERT (is_open (fd));
111 /* Ignore any other fd's leaked into this process. */
114 ASSERT (!is_open (fd + 1));
115 ASSERT (!is_open (fd + 2));
117 /* Assigning to self must be a no-op. */
118 ASSERT (dup2 (fd, fd) == fd);
119 ASSERT (is_open (fd));
121 /* The source must be valid. */
123 ASSERT (dup2 (-1, fd) == -1);
124 ASSERT (errno == EBADF);
127 ASSERT (dup2 (99, fd) == -1);
128 ASSERT (errno == EBADF);
130 ASSERT (dup2 (AT_FDCWD, fd) == -1);
131 ASSERT (errno == EBADF);
132 ASSERT (is_open (fd));
134 /* If the source is not open, then the destination is unaffected. */
136 ASSERT (dup2 (fd + 1, fd + 1) == -1);
137 ASSERT (errno == EBADF);
138 ASSERT (!is_open (fd + 1));
140 ASSERT (dup2 (fd + 1, fd) == -1);
141 ASSERT (errno == EBADF);
142 ASSERT (is_open (fd));
144 /* The destination must be valid. */
146 ASSERT (dup2 (fd, -2) == -1);
147 ASSERT (errno == EBADF);
149 ASSERT (dup2 (fd, 10000000) == -1);
150 ASSERT (errno == EBADF);
152 /* Using dup2 can skip fds. */
153 ASSERT (dup2 (fd, fd + 2) == fd + 2);
154 ASSERT (is_open (fd));
155 ASSERT (!is_open (fd + 1));
156 ASSERT (is_open (fd + 2));
158 /* Verify that dup2 closes the previous occupant of a fd. */
159 ASSERT (open ("/dev/null", O_WRONLY, 0600) == fd + 1);
160 ASSERT (dup2 (fd + 1, fd) == fd);
161 ASSERT (close (fd + 1) == 0);
162 ASSERT (write (fd, "1", 1) == 1);
163 ASSERT (dup2 (fd + 2, fd) == fd);
164 ASSERT (lseek (fd, 0, SEEK_END) == 0);
165 ASSERT (write (fd + 2, "2", 1) == 1);
166 ASSERT (lseek (fd, 0, SEEK_SET) == 0);
167 ASSERT (read (fd, buffer, 1) == 1);
168 ASSERT (*buffer == '2');
170 #if GNULIB_TEST_CLOEXEC
171 /* Any new fd created by dup2 must not be cloexec. */
172 ASSERT (close (fd + 2) == 0);
173 ASSERT (dup_cloexec (fd) == fd + 1);
174 ASSERT (!is_inheritable (fd + 1));
175 ASSERT (dup2 (fd + 1, fd + 1) == fd + 1);
176 ASSERT (!is_inheritable (fd + 1));
177 ASSERT (dup2 (fd + 1, fd + 2) == fd + 2);
178 ASSERT (!is_inheritable (fd + 1));
179 ASSERT (is_inheritable (fd + 2));
181 ASSERT (dup2 (fd + 1, -1) == -1);
182 ASSERT (errno == EBADF);
183 ASSERT (!is_inheritable (fd + 1));
186 /* On systems that distinguish between text and binary mode, dup2
187 reuses the mode of the source. */
188 setmode (fd, O_BINARY);
189 ASSERT (is_mode (fd, O_BINARY));
190 ASSERT (dup2 (fd, fd + 1) == fd + 1);
191 ASSERT (is_mode (fd + 1, O_BINARY));
192 setmode (fd, O_TEXT);
193 ASSERT (is_mode (fd, O_TEXT));
194 ASSERT (dup2 (fd, fd + 1) == fd + 1);
195 ASSERT (is_mode (fd + 1, O_TEXT));
198 ASSERT (close (fd + 2) == 0);
199 ASSERT (close (fd + 1) == 0);
200 ASSERT (close (fd) == 0);
201 ASSERT (unlink (file) == 0);