From 3bebb94360f1c2333feb8d504a9fa4f96984d8b7 Mon Sep 17 00:00:00 2001 From: Andreas Rottmann Date: Mon, 14 Sep 2009 12:34:37 +0200 Subject: Imported Upstream version 0.9.1.1 --- lib/dup2.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 lib/dup2.c (limited to 'lib/dup2.c') diff --git a/lib/dup2.c b/lib/dup2.c new file mode 100644 index 00000000..a7d3cfd7 --- /dev/null +++ b/lib/dup2.c @@ -0,0 +1,97 @@ +/* Duplicate an open file descriptor to a specified file descriptor. + + Copyright (C) 1999, 2004, 2005, 2006, 2007, 2009 Free Software + Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see . */ + +/* written by Paul Eggert */ + +#include + +/* Specification. */ +#include + +#include +#include + +#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ +/* Get declarations of the Win32 API functions. */ +# define WIN32_LEAN_AND_MEAN +# include +#endif + +#if REPLACE_DUP2 + +# undef dup2 + +int +rpl_dup2 (int fd, int desired_fd) +{ + int result; +# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ + /* If fd is closed, mingw hangs on dup2 (fd, fd). If fd is open, + dup2 (fd, fd) returns 0, but all further attempts to use fd in + future dup2 calls will hang. */ + if (fd == desired_fd) + { + if ((HANDLE) _get_osfhandle (fd) == INVALID_HANDLE_VALUE) + { + errno = EBADF; + return -1; + } + return fd; + } +# endif + result = dup2 (fd, desired_fd); + if (result == 0) + result = desired_fd; + return result; +} + +#else /* !REPLACE_DUP2 */ + +/* On older platforms, dup2 did not exist. */ + +# ifndef F_DUPFD +static int +dupfd (int fd, int desired_fd) +{ + int duplicated_fd = dup (fd); + if (duplicated_fd < 0 || duplicated_fd == desired_fd) + return duplicated_fd; + else + { + int r = dupfd (fd, desired_fd); + int e = errno; + close (duplicated_fd); + errno = e; + return r; + } +} +# endif + +int +dup2 (int fd, int desired_fd) +{ + if (fd == desired_fd) + return fd; + close (desired_fd); +# ifdef F_DUPFD + return fcntl (fd, F_DUPFD, desired_fd); +# else + return dupfd (fd, desired_fd); +# endif +} +#endif /* !REPLACE_DUP2 */ -- cgit v1.2.3