summaryrefslogtreecommitdiffstats
path: root/lib/freopen.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 16:11:47 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 16:11:47 +0000
commit758f820bcc0f68aeebac1717e537ca13a320b909 (patch)
tree48111ece75cf4f98316848b37a7e26356e00669e /lib/freopen.c
parentInitial commit. (diff)
downloadcoreutils-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.c92
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;
+}