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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:11:47 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:11:47 +0000 |
commit | 758f820bcc0f68aeebac1717e537ca13a320b909 (patch) | |
tree | 48111ece75cf4f98316848b37a7e26356e00669e /lib/freopen.c | |
parent | Initial commit. (diff) | |
download | coreutils-758f820bcc0f68aeebac1717e537ca13a320b909.tar.xz coreutils-758f820bcc0f68aeebac1717e537ca13a320b909.zip |
Adding upstream version 9.1.upstream/9.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/freopen.c')
-rw-r--r-- | lib/freopen.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/lib/freopen.c b/lib/freopen.c new file mode 100644 index 0000000..4988e71 --- /dev/null +++ b/lib/freopen.c @@ -0,0 +1,92 @@ +/* Open a stream to a file. + Copyright (C) 2007-2022 Free Software Foundation, Inc. + + This file 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 file 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 <https://www.gnu.org/licenses/>. */ + +/* Written by Bruno Haible <bruno@clisp.org>, 2007. */ + +/* If the user's config.h happens to include <stdio.h>, let it include only + the system's <stdio.h> here, so that orig_freopen doesn't recurse to + rpl_freopen. */ +#define _GL_ALREADY_INCLUDING_STDIO_H +#include <config.h> + +/* Get the original definition of freopen. It might be defined as a macro. */ +#include <stdio.h> +#undef _GL_ALREADY_INCLUDING_STDIO_H + +#include <errno.h> + +static FILE * +orig_freopen (const char *filename, const char *mode, FILE *stream) +{ + return freopen (filename, mode, stream); +} + +/* Specification. */ +/* Write "stdio.h" here, not <stdio.h>, otherwise OSF/1 5.1 DTK cc eliminates + this include because of the preliminary #include <stdio.h> above. */ +#include "stdio.h" + +#include <fcntl.h> +#include <string.h> +#include <unistd.h> + +FILE * +rpl_freopen (const char *filename, const char *mode, FILE *stream) +{ + FILE *result; +#if defined _WIN32 && ! defined __CYGWIN__ + char const *null_device = "NUL"; + if (filename && strcmp (filename, "/dev/null") == 0) + filename = null_device; +#else + char const *null_device = "/dev/null"; +#endif + +#ifdef __KLIBC__ + errno = 0; +#endif + + result = orig_freopen (filename, mode, stream); + + if (!result) + { +#ifdef __KLIBC__ + /* On OS/2 kLIBC, freopen returns NULL even if it is successful + if filename is NULL. */ + if (!filename && !errno) + result = stream; +#endif + } + else if (filename) + { + int fd = fileno (result); + if (dup2 (fd, fd) < 0 && errno == EBADF) + { + int nullfd = open (null_device, O_RDONLY | O_CLOEXEC); + int err = 0; + if (nullfd != fd) + { + if (dup2 (nullfd, fd) < 0) + err = 1; + close (nullfd); + } + if (!err) + result = orig_freopen (filename, mode, result); + } + } + + return result; +} |