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+/* POSIX compatible read() function.
+ Copyright (C) 2008-2023 Free Software Foundation, Inc.
+ Written by Bruno Haible <bruno@clisp.org>, 2011.
+
+ 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 2.1 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/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include <unistd.h>
+
+#if defined _WIN32 && ! defined __CYGWIN__
+
+# include <errno.h>
+# include <io.h>
+
+# define WIN32_LEAN_AND_MEAN /* avoid including junk */
+# include <windows.h>
+
+# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+# include "msvc-inval.h"
+# endif
+# if GNULIB_MSVC_NOTHROW
+# include "msvc-nothrow.h"
+# else
+# include <io.h>
+# endif
+
+/* Don't assume that UNICODE is not defined. */
+# undef GetNamedPipeHandleState
+# define GetNamedPipeHandleState GetNamedPipeHandleStateA
+
+# undef read
+
+# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+static ssize_t
+read_nothrow (int fd, void *buf, size_t count)
+{
+ ssize_t result;
+
+ TRY_MSVC_INVAL
+ {
+ result = _read (fd, buf, count);
+ }
+ CATCH_MSVC_INVAL
+ {
+ result = -1;
+ errno = EBADF;
+ }
+ DONE_MSVC_INVAL;
+
+ return result;
+}
+# else
+# define read_nothrow _read
+# endif
+
+ssize_t
+rpl_read (int fd, void *buf, size_t count)
+{
+ ssize_t ret = read_nothrow (fd, buf, count);
+
+# if GNULIB_NONBLOCKING
+ if (ret < 0
+ && GetLastError () == ERROR_NO_DATA)
+ {
+ HANDLE h = (HANDLE) _get_osfhandle (fd);
+ if (GetFileType (h) == FILE_TYPE_PIPE)
+ {
+ /* h is a pipe or socket. */
+ DWORD state;
+ if (GetNamedPipeHandleState (h, &state, NULL, NULL, NULL, NULL, 0)
+ && (state & PIPE_NOWAIT) != 0)
+ /* h is a pipe in non-blocking mode.
+ Change errno from EINVAL to EAGAIN. */
+ errno = EAGAIN;
+ }
+ }
+# endif
+
+ return ret;
+}
+
+#endif