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

169 lines
5.9 KiB
C

/* POSIX compatible FILE stream 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 <stdio.h>
/* Replace these functions only if module 'nonblocking' is requested. */
#if GNULIB_NONBLOCKING
/* On native Windows platforms, when read() is called on a non-blocking pipe
with an empty buffer, ReadFile() fails with error GetLastError() =
ERROR_NO_DATA, and read() in consequence fails with error EINVAL. This
read() function is at the basis of the function which fills the buffer of
a FILE stream. */
# if defined _WIN32 && ! defined __CYGWIN__
# include <errno.h>
# include <io.h>
# define WIN32_LEAN_AND_MEAN /* avoid including junk */
# include <windows.h>
# 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
# define CALL_WITH_ERRNO_FIX(RETTYPE, EXPRESSION, FAILED) \
if (ferror (stream)) \
return (EXPRESSION); \
else \
{ \
RETTYPE ret; \
SetLastError (0); \
ret = (EXPRESSION); \
if (FAILED) \
{ \
if (GetLastError () == ERROR_NO_DATA && ferror (stream)) \
{ \
int fd = fileno (stream); \
if (fd >= 0) \
{ \
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; \
} \
} \
} \
} \
return ret; \
}
/* Enable this function definition only if gnulib's <stdio.h> has prepared it.
Otherwise we get a function definition conflict with mingw64's <stdio.h>. */
# if GNULIB_SCANF
int
scanf (const char *format, ...)
{
int retval;
va_list args;
va_start (args, format);
retval = vfscanf (stdin, format, args);
va_end (args);
return retval;
}
# endif
/* Enable this function definition only if gnulib's <stdio.h> has prepared it.
Otherwise we get a function definition conflict with mingw64's <stdio.h>. */
# if GNULIB_FSCANF
int
fscanf (FILE *stream, const char *format, ...)
{
int retval;
va_list args;
va_start (args, format);
retval = vfscanf (stream, format, args);
va_end (args);
return retval;
}
# endif
/* Enable this function definition only if gnulib's <stdio.h> has prepared it.
Otherwise we get a function definition conflict with mingw64's <stdio.h>. */
# if GNULIB_VSCANF
int
vscanf (const char *format, va_list args)
{
return vfscanf (stdin, format, args);
}
# endif
/* Enable this function definition only if gnulib's <stdio.h> has prepared it.
Otherwise we get a function definition conflict with mingw64's <stdio.h>. */
# if GNULIB_VFSCANF
int
vfscanf (FILE *stream, const char *format, va_list args)
#undef vfscanf
{
CALL_WITH_ERRNO_FIX (int, vfscanf (stream, format, args), ret == EOF)
}
# endif
int
getchar (void)
{
return fgetc (stdin);
}
int
fgetc (FILE *stream)
#undef fgetc
{
CALL_WITH_ERRNO_FIX (int, fgetc (stream), ret == EOF)
}
char *
fgets (char *s, int n, FILE *stream)
#undef fgets
{
CALL_WITH_ERRNO_FIX (char *, fgets (s, n, stream), ret == NULL)
}
/* We intentionally don't bother to fix gets. */
size_t
fread (void *ptr, size_t s, size_t n, FILE *stream)
#undef fread
{
CALL_WITH_ERRNO_FIX (size_t, fread (ptr, s, n, stream), ret < n)
}
# endif
#endif