1 /* Copy a file descriptor, applying specific flags.
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 2, or (at your option)
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 along
15 with this program; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
27 #include "binary-io.h"
29 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
30 /* Native Woe32 API. */
34 /* Get declarations of the Win32 API functions. */
35 # define WIN32_LEAN_AND_MEAN
38 /* Upper bound on getdtablesize(). See lib/getdtablesize.c. */
39 # define OPEN_MAX_MAX 0x10000
44 dup3 (int oldfd, int newfd, int flags)
48 /* Try the system call first, if it exists. (We may be running with a glibc
49 that has the function but with an older kernel that lacks it.) */
51 /* Cache the information whether the system call really exists. */
52 static int have_dup3_really; /* 0 = unknown, 1 = yes, -1 = no */
53 if (have_dup3_really >= 0)
55 int result = dup3 (oldfd, newfd, flags);
56 if (!(result < 0 && errno == ENOSYS))
61 result = _gl_register_dup (oldfd, newfd);
65 have_dup3_really = -1;
70 if (newfd < 0 || newfd >= getdtablesize () || fcntl (oldfd, F_GETFD) == -1)
82 /* Check the supported flags.
83 Note that O_NONBLOCK is not supported, because setting it on newfd
84 would implicitly also set it on oldfd. */
85 if ((flags & ~(O_CLOEXEC | O_BINARY | O_TEXT)) != 0)
91 if (flags & O_CLOEXEC)
95 result = fcntl (oldfd, F_DUPFD_CLOEXEC, newfd);
105 else if (dup2 (oldfd, newfd) < 0)
109 if (flags & O_BINARY)
110 setmode (newfd, O_BINARY);
111 else if (flags & O_TEXT)
112 setmode (newfd, O_TEXT);