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3dac6181 AW |
1 | /* Duplicate an open file descriptor to a specified file descriptor. |
2 | ||
5e69ceb7 | 3 | Copyright (C) 1999, 2004-2007, 2009-2014 Free Software Foundation, Inc. |
3dac6181 AW |
4 | |
5 | This program is free software: you can redistribute it and/or modify | |
6 | it under the terms of the GNU Lesser General Public License as published by | |
7 | the Free Software Foundation; either version 3 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program 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 | |
13 | GNU Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public License | |
16 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
17 | ||
18 | /* written by Paul Eggert */ | |
19 | ||
20 | #include <config.h> | |
21 | ||
22 | /* Specification. */ | |
23 | #include <unistd.h> | |
24 | ||
25 | #include <errno.h> | |
26 | #include <fcntl.h> | |
27 | ||
28 | #if HAVE_DUP2 | |
29 | ||
30 | # undef dup2 | |
31 | ||
32 | # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ | |
33 | ||
34 | /* Get declarations of the native Windows API functions. */ | |
35 | # define WIN32_LEAN_AND_MEAN | |
36 | # include <windows.h> | |
37 | ||
38 | # include "msvc-inval.h" | |
39 | ||
40 | /* Get _get_osfhandle. */ | |
41 | # include "msvc-nothrow.h" | |
42 | ||
43 | static int | |
44 | ms_windows_dup2 (int fd, int desired_fd) | |
45 | { | |
46 | int result; | |
47 | ||
48 | /* If fd is closed, mingw hangs on dup2 (fd, fd). If fd is open, | |
49 | dup2 (fd, fd) returns 0, but all further attempts to use fd in | |
50 | future dup2 calls will hang. */ | |
51 | if (fd == desired_fd) | |
52 | { | |
53 | if ((HANDLE) _get_osfhandle (fd) == INVALID_HANDLE_VALUE) | |
54 | { | |
55 | errno = EBADF; | |
56 | return -1; | |
57 | } | |
58 | return fd; | |
59 | } | |
60 | ||
61 | /* Wine 1.0.1 return 0 when desired_fd is negative but not -1: | |
62 | http://bugs.winehq.org/show_bug.cgi?id=21289 */ | |
63 | if (desired_fd < 0) | |
64 | { | |
65 | errno = EBADF; | |
66 | return -1; | |
67 | } | |
68 | ||
69 | TRY_MSVC_INVAL | |
70 | { | |
71 | result = dup2 (fd, desired_fd); | |
72 | } | |
73 | CATCH_MSVC_INVAL | |
74 | { | |
75 | errno = EBADF; | |
76 | result = -1; | |
77 | } | |
78 | DONE_MSVC_INVAL; | |
79 | ||
80 | if (result == 0) | |
81 | result = desired_fd; | |
82 | ||
83 | return result; | |
84 | } | |
85 | ||
86 | # define dup2 ms_windows_dup2 | |
87 | ||
88 | # endif | |
89 | ||
90 | int | |
91 | rpl_dup2 (int fd, int desired_fd) | |
92 | { | |
93 | int result; | |
94 | ||
95 | # ifdef F_GETFL | |
96 | /* On Linux kernels 2.6.26-2.6.29, dup2 (fd, fd) returns -EBADF. | |
97 | On Cygwin 1.5.x, dup2 (1, 1) returns 0. | |
98 | On Cygwin 1.7.17, dup2 (1, -1) dumps core. | |
5e69ceb7 | 99 | On Cygwin 1.7.25, dup2 (1, 256) can dump core. |
3dac6181 | 100 | On Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC. */ |
5e69ceb7 MW |
101 | # if HAVE_SETDTABLESIZE |
102 | setdtablesize (desired_fd + 1); | |
103 | # endif | |
3dac6181 AW |
104 | if (desired_fd < 0) |
105 | fd = desired_fd; | |
106 | if (fd == desired_fd) | |
107 | return fcntl (fd, F_GETFL) == -1 ? -1 : fd; | |
108 | # endif | |
109 | ||
110 | result = dup2 (fd, desired_fd); | |
111 | ||
112 | /* Correct an errno value on FreeBSD 6.1 and Cygwin 1.5.x. */ | |
113 | if (result == -1 && errno == EMFILE) | |
114 | errno = EBADF; | |
115 | # if REPLACE_FCHDIR | |
116 | if (fd != desired_fd && result != -1) | |
117 | result = _gl_register_dup (fd, result); | |
118 | # endif | |
119 | return result; | |
120 | } | |
121 | ||
122 | #else /* !HAVE_DUP2 */ | |
123 | ||
124 | /* On older platforms, dup2 did not exist. */ | |
125 | ||
126 | # ifndef F_DUPFD | |
127 | static int | |
128 | dupfd (int fd, int desired_fd) | |
129 | { | |
130 | int duplicated_fd = dup (fd); | |
131 | if (duplicated_fd < 0 || duplicated_fd == desired_fd) | |
132 | return duplicated_fd; | |
133 | else | |
134 | { | |
135 | int r = dupfd (fd, desired_fd); | |
136 | int e = errno; | |
137 | close (duplicated_fd); | |
138 | errno = e; | |
139 | return r; | |
140 | } | |
141 | } | |
142 | # endif | |
143 | ||
144 | int | |
145 | dup2 (int fd, int desired_fd) | |
146 | { | |
147 | int result = fcntl (fd, F_GETFL) < 0 ? -1 : fd; | |
148 | if (result == -1 || fd == desired_fd) | |
149 | return result; | |
150 | close (desired_fd); | |
151 | # ifdef F_DUPFD | |
152 | result = fcntl (fd, F_DUPFD, desired_fd); | |
153 | # if REPLACE_FCHDIR | |
154 | if (0 <= result) | |
155 | result = _gl_register_dup (fd, result); | |
156 | # endif | |
157 | # else | |
158 | result = dupfd (fd, desired_fd); | |
159 | # endif | |
160 | if (result == -1 && (errno == EMFILE || errno == EINVAL)) | |
161 | errno = EBADF; | |
162 | return result; | |
163 | } | |
164 | #endif /* !HAVE_DUP2 */ |