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-rw-r--r--REORG.TODO/sysdeps/posix/pwrite64.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/posix/pwrite64.c b/REORG.TODO/sysdeps/posix/pwrite64.c
new file mode 100644
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+++ b/REORG.TODO/sysdeps/posix/pwrite64.c
@@ -0,0 +1,62 @@
+/* Write block to given position in file without changing file pointer.
+ POSIX version.
+ Copyright (C) 1997-2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+ The GNU C Library 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 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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 the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <unistd.h>
+
+/* Note: This implementation of pwrite64 is not multithread-safe. */
+
+ssize_t
+__libc_pwrite64 (int fd, const void *buf, size_t nbyte, off64_t offset)
+{
+ /* Since we must not change the file pointer preserve the value so that
+ we can restore it later. */
+ int save_errno;
+ ssize_t result;
+ off64_t old_offset = __libc_lseek64 (fd, 0, SEEK_CUR);
+ if (old_offset == (off64_t) -1)
+ return -1;
+
+ /* Set to wanted position. */
+ if (__libc_lseek64 (fd, offset, SEEK_SET) == (off64_t) -1)
+ return -1;
+
+ /* Write out the data. */
+ result = __libc_write (fd, buf, nbyte);
+
+ /* Now we have to restore the position. If this fails we have to
+ return this as an error. But if the writing also failed we
+ return this error. */
+ save_errno = errno;
+ if (__libc_lseek64 (fd, old_offset, SEEK_SET) == (off64_t) -1)
+ {
+ if (result == -1)
+ __set_errno (save_errno);
+ return -1;
+ }
+ __set_errno (save_errno);
+
+ return result;
+}
+#ifndef __libc_pwrite64
+weak_alias (__libc_pwrite64, __pwrite64)
+libc_hidden_weak (__pwrite64)
+weak_alias (__libc_pwrite64, pwrite64)
+#endif