Commit | Line | Data |
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7a7ef429 PE |
1 | /* Duplicate an open file descriptor to a specified file descriptor. |
2 | ||
3 | Copyright (C) 1999, 2004-2007, 2009-2011 Free Software Foundation, Inc. | |
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 | |
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 (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ | |
29 | /* Get declarations of the Win32 API functions. */ | |
30 | # define WIN32_LEAN_AND_MEAN | |
31 | # include <windows.h> | |
32 | #endif | |
33 | ||
34 | #if HAVE_DUP2 | |
35 | ||
36 | # undef dup2 | |
37 | ||
38 | int | |
39 | rpl_dup2 (int fd, int desired_fd) | |
40 | { | |
41 | int result; | |
42 | # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ | |
43 | /* If fd is closed, mingw hangs on dup2 (fd, fd). If fd is open, | |
44 | dup2 (fd, fd) returns 0, but all further attempts to use fd in | |
45 | future dup2 calls will hang. */ | |
46 | if (fd == desired_fd) | |
47 | { | |
48 | if ((HANDLE) _get_osfhandle (fd) == INVALID_HANDLE_VALUE) | |
49 | { | |
50 | errno = EBADF; | |
51 | return -1; | |
52 | } | |
53 | return fd; | |
54 | } | |
55 | /* Wine 1.0.1 return 0 when desired_fd is negative but not -1: | |
56 | http://bugs.winehq.org/show_bug.cgi?id=21289 */ | |
57 | if (desired_fd < 0) | |
58 | { | |
59 | errno = EBADF; | |
60 | return -1; | |
61 | } | |
62 | # elif !defined __linux__ | |
63 | /* On Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC. */ | |
64 | if (fd == desired_fd) | |
65 | return fcntl (fd, F_GETFL) == -1 ? -1 : fd; | |
66 | # endif | |
67 | result = dup2 (fd, desired_fd); | |
68 | # ifdef __linux__ | |
69 | /* Correct a Linux return value. | |
70 | <http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.30.y.git;a=commitdiff;h=2b79bc4f7ebbd5af3c8b867968f9f15602d5f802> | |
71 | */ | |
72 | if (fd == desired_fd && result == (unsigned int) -EBADF) | |
73 | { | |
74 | errno = EBADF; | |
75 | result = -1; | |
76 | } | |
77 | # endif | |
78 | if (result == 0) | |
79 | result = desired_fd; | |
80 | /* Correct a cygwin 1.5.x errno value. */ | |
81 | else if (result == -1 && errno == EMFILE) | |
82 | errno = EBADF; | |
83 | # if REPLACE_FCHDIR | |
84 | if (fd != desired_fd && result != -1) | |
85 | result = _gl_register_dup (fd, result); | |
86 | # endif | |
87 | return result; | |
88 | } | |
89 | ||
90 | #else /* !HAVE_DUP2 */ | |
91 | ||
92 | /* On older platforms, dup2 did not exist. */ | |
93 | ||
94 | # ifndef F_DUPFD | |
95 | static int | |
96 | dupfd (int fd, int desired_fd) | |
97 | { | |
98 | int duplicated_fd = dup (fd); | |
99 | if (duplicated_fd < 0 || duplicated_fd == desired_fd) | |
100 | return duplicated_fd; | |
101 | else | |
102 | { | |
103 | int r = dupfd (fd, desired_fd); | |
104 | int e = errno; | |
105 | close (duplicated_fd); | |
106 | errno = e; | |
107 | return r; | |
108 | } | |
109 | } | |
110 | # endif | |
111 | ||
112 | int | |
113 | dup2 (int fd, int desired_fd) | |
114 | { | |
115 | int result = fcntl (fd, F_GETFL) < 0 ? -1 : fd; | |
116 | if (result == -1 || fd == desired_fd) | |
117 | return result; | |
118 | close (desired_fd); | |
119 | # ifdef F_DUPFD | |
120 | result = fcntl (fd, F_DUPFD, desired_fd); | |
121 | # if REPLACE_FCHDIR | |
122 | if (0 <= result) | |
123 | result = _gl_register_dup (fd, result); | |
124 | # endif | |
125 | # else | |
126 | result = dupfd (fd, desired_fd); | |
127 | # endif | |
128 | if (result == -1 && (errno == EMFILE || errno == EINVAL)) | |
129 | errno = EBADF; | |
130 | return result; | |
131 | } | |
132 | #endif /* !HAVE_DUP2 */ |