rm_/lib/read.c
2022-07-28 14:16:50 +08:00

96 lines
2.3 KiB
C

/* POSIX compatible read() function.
Copyright (C) 2008-2022 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