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6ec2e0f5 SDJ |
1 | /* Duplicate an open file descriptor to a specified file descriptor. |
2 | ||
9c9d63b1 | 3 | Copyright (C) 1999, 2004-2007, 2009-2021 Free Software Foundation, Inc. |
6ec2e0f5 SDJ |
4 | |
5 | This program is free software: you can redistribute it and/or modify | |
6 | it under the terms of the GNU 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 General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
c0c3707f | 16 | along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
6ec2e0f5 SDJ |
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 | ||
9c9d63b1 | 28 | #undef dup2 |
6ec2e0f5 | 29 | |
9c9d63b1 | 30 | #if defined _WIN32 && ! defined __CYGWIN__ |
6ec2e0f5 SDJ |
31 | |
32 | /* Get declarations of the native Windows API functions. */ | |
9c9d63b1 PM |
33 | # define WIN32_LEAN_AND_MEAN |
34 | # include <windows.h> | |
6ec2e0f5 | 35 | |
9c9d63b1 PM |
36 | # if HAVE_MSVC_INVALID_PARAMETER_HANDLER |
37 | # include "msvc-inval.h" | |
38 | # endif | |
6ec2e0f5 SDJ |
39 | |
40 | /* Get _get_osfhandle. */ | |
9c9d63b1 PM |
41 | # if GNULIB_MSVC_NOTHROW |
42 | # include "msvc-nothrow.h" | |
43 | # else | |
44 | # include <io.h> | |
45 | # endif | |
c0c3707f | 46 | |
9c9d63b1 | 47 | # if HAVE_MSVC_INVALID_PARAMETER_HANDLER |
c0c3707f CB |
48 | static int |
49 | dup2_nothrow (int fd, int desired_fd) | |
50 | { | |
51 | int result; | |
52 | ||
53 | TRY_MSVC_INVAL | |
54 | { | |
9c9d63b1 | 55 | result = _dup2 (fd, desired_fd); |
c0c3707f CB |
56 | } |
57 | CATCH_MSVC_INVAL | |
58 | { | |
59 | errno = EBADF; | |
60 | result = -1; | |
61 | } | |
62 | DONE_MSVC_INVAL; | |
63 | ||
64 | return result; | |
65 | } | |
9c9d63b1 PM |
66 | # else |
67 | # define dup2_nothrow _dup2 | |
68 | # endif | |
6ec2e0f5 SDJ |
69 | |
70 | static int | |
71 | ms_windows_dup2 (int fd, int desired_fd) | |
72 | { | |
73 | int result; | |
74 | ||
75 | /* If fd is closed, mingw hangs on dup2 (fd, fd). If fd is open, | |
76 | dup2 (fd, fd) returns 0, but all further attempts to use fd in | |
77 | future dup2 calls will hang. */ | |
78 | if (fd == desired_fd) | |
79 | { | |
80 | if ((HANDLE) _get_osfhandle (fd) == INVALID_HANDLE_VALUE) | |
81 | { | |
82 | errno = EBADF; | |
83 | return -1; | |
84 | } | |
85 | return fd; | |
86 | } | |
87 | ||
88 | /* Wine 1.0.1 return 0 when desired_fd is negative but not -1: | |
c0c3707f | 89 | https://bugs.winehq.org/show_bug.cgi?id=21289 */ |
6ec2e0f5 SDJ |
90 | if (desired_fd < 0) |
91 | { | |
92 | errno = EBADF; | |
93 | return -1; | |
94 | } | |
95 | ||
c0c3707f | 96 | result = dup2_nothrow (fd, desired_fd); |
6ec2e0f5 SDJ |
97 | |
98 | if (result == 0) | |
99 | result = desired_fd; | |
100 | ||
101 | return result; | |
102 | } | |
103 | ||
9c9d63b1 | 104 | # define dup2 ms_windows_dup2 |
6ec2e0f5 | 105 | |
9c9d63b1 | 106 | #elif defined __KLIBC__ |
6ec2e0f5 | 107 | |
9c9d63b1 | 108 | # include <InnoTekLIBC/backend.h> |
6ec2e0f5 SDJ |
109 | |
110 | static int | |
111 | klibc_dup2dirfd (int fd, int desired_fd) | |
112 | { | |
113 | int tempfd; | |
114 | int dupfd; | |
115 | ||
116 | tempfd = open ("NUL", O_RDONLY); | |
117 | if (tempfd == -1) | |
118 | return -1; | |
119 | ||
120 | if (tempfd == desired_fd) | |
121 | { | |
122 | close (tempfd); | |
123 | ||
124 | char path[_MAX_PATH]; | |
125 | if (__libc_Back_ioFHToPath (fd, path, sizeof (path))) | |
126 | return -1; | |
127 | ||
128 | return open(path, O_RDONLY); | |
129 | } | |
130 | ||
131 | dupfd = klibc_dup2dirfd (fd, desired_fd); | |
132 | ||
133 | close (tempfd); | |
134 | ||
135 | return dupfd; | |
136 | } | |
137 | ||
138 | static int | |
139 | klibc_dup2 (int fd, int desired_fd) | |
140 | { | |
141 | int dupfd; | |
142 | struct stat sbuf; | |
143 | ||
144 | dupfd = dup2 (fd, desired_fd); | |
145 | if (dupfd == -1 && errno == ENOTSUP \ | |
146 | && !fstat (fd, &sbuf) && S_ISDIR (sbuf.st_mode)) | |
147 | { | |
148 | close (desired_fd); | |
149 | ||
150 | return klibc_dup2dirfd (fd, desired_fd); | |
151 | } | |
152 | ||
153 | return dupfd; | |
154 | } | |
155 | ||
9c9d63b1 PM |
156 | # define dup2 klibc_dup2 |
157 | #endif | |
6ec2e0f5 SDJ |
158 | |
159 | int | |
160 | rpl_dup2 (int fd, int desired_fd) | |
161 | { | |
162 | int result; | |
163 | ||
9c9d63b1 | 164 | #ifdef F_GETFL |
6ec2e0f5 SDJ |
165 | /* On Linux kernels 2.6.26-2.6.29, dup2 (fd, fd) returns -EBADF. |
166 | On Cygwin 1.5.x, dup2 (1, 1) returns 0. | |
167 | On Cygwin 1.7.17, dup2 (1, -1) dumps core. | |
168 | On Cygwin 1.7.25, dup2 (1, 256) can dump core. | |
169 | On Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC. */ | |
9c9d63b1 | 170 | # if HAVE_SETDTABLESIZE |
6ec2e0f5 | 171 | setdtablesize (desired_fd + 1); |
9c9d63b1 | 172 | # endif |
6ec2e0f5 SDJ |
173 | if (desired_fd < 0) |
174 | fd = desired_fd; | |
175 | if (fd == desired_fd) | |
176 | return fcntl (fd, F_GETFL) == -1 ? -1 : fd; | |
9c9d63b1 | 177 | #endif |
6ec2e0f5 SDJ |
178 | |
179 | result = dup2 (fd, desired_fd); | |
180 | ||
181 | /* Correct an errno value on FreeBSD 6.1 and Cygwin 1.5.x. */ | |
182 | if (result == -1 && errno == EMFILE) | |
183 | errno = EBADF; | |
9c9d63b1 | 184 | #if REPLACE_FCHDIR |
6ec2e0f5 SDJ |
185 | if (fd != desired_fd && result != -1) |
186 | result = _gl_register_dup (fd, result); | |
9c9d63b1 | 187 | #endif |
6ec2e0f5 SDJ |
188 | return result; |
189 | } |