diff options
Diffstat (limited to 'lib/stdio-read.c')
| -rw-r--r-- | lib/stdio-read.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/lib/stdio-read.c b/lib/stdio-read.c new file mode 100644 index 0000000..6e2984c --- /dev/null +++ b/lib/stdio-read.c @@ -0,0 +1,168 @@ +/* POSIX compatible FILE stream 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 <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 |