lib/stdio-write.c

   1 /* POSIX compatible FILE stream write function.
   2    Copyright (C) 2008-2014 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2008.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 /* Specification.  */
  21 #include <stdio.h>
  22
  23 /* Replace these functions only if module 'nonblocking' or module 'sigpipe' is
  24    requested.  */
  25 #if GNULIB_NONBLOCKING || GNULIB_SIGPIPE
  26
  27 /* On native Windows platforms, SIGPIPE does not exist.  When write() is
  28    called on a pipe with no readers, WriteFile() fails with error
  29    GetLastError() = ERROR_NO_DATA, and write() in consequence fails with
  30    error EINVAL.  This write() function is at the basis of the function
  31    which flushes the buffer of a FILE stream.  */
  32
  33 # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  34
  35 #  include <errno.h>
  36 #  include <signal.h>
  37 #  include <io.h>
  38
  39 #  define WIN32_LEAN_AND_MEAN  /* avoid including junk */
  40 #  include <windows.h>
  41
  42 #  include "msvc-nothrow.h"
  43
  44 #  if GNULIB_NONBLOCKING
  45 #   define CLEAR_ERRNO \
  46       errno = 0;
  47 #   define HANDLE_ENOSPC \
  48           if (errno == ENOSPC && ferror (stream))                             \
  49             {                                                                 \
  50               int fd = fileno (stream);                                       \
  51               if (fd >= 0)                                                    \
  52                 {                                                             \
  53                   HANDLE h = (HANDLE) _get_osfhandle (fd);                    \
  54                   if (GetFileType (h) == FILE_TYPE_PIPE)                      \
  55                     {                                                         \
  56                       /* h is a pipe or socket.  */                           \
  57                       DWORD state;                                            \
  58                       if (GetNamedPipeHandleState (h, &state, NULL, NULL,     \
  59                                                    NULL, NULL, 0)             \
  60                           && (state & PIPE_NOWAIT) != 0)                      \
  61                         /* h is a pipe in non-blocking mode.                  \
  62                            Change errno from ENOSPC to EAGAIN.  */            \
  63                         errno = EAGAIN;                                       \
  64                     }                                                         \
  65                 }                                                             \
  66             }                                                                 \
  67           else
  68 #  else
  69 #   define CLEAR_ERRNO
  70 #   define HANDLE_ENOSPC
  71 #  endif
  72
  73 #  if GNULIB_SIGPIPE
  74 #   define CLEAR_LastError \
  75       SetLastError (0);
  76 #   define HANDLE_ERROR_NO_DATA \
  77           if (GetLastError () == ERROR_NO_DATA && ferror (stream))            \
  78             {                                                                 \
  79               int fd = fileno (stream);                                       \
  80               if (fd >= 0                                                     \
  81                   && GetFileType ((HANDLE) _get_osfhandle (fd))               \
  82                      == FILE_TYPE_PIPE)                                       \
  83                 {                                                             \
  84                   /* Try to raise signal SIGPIPE.  */                         \
  85                   raise (SIGPIPE);                                            \
  86                   /* If it is currently blocked or ignored, change errno from \
  87                      EINVAL to EPIPE.  */                                     \
  88                   errno = EPIPE;                                              \
  89                 }                                                             \
  90             }                                                                 \
  91           else
  92 #  else
  93 #   define CLEAR_LastError
  94 #   define HANDLE_ERROR_NO_DATA
  95 #  endif
  96
  97 #  define CALL_WITH_SIGPIPE_EMULATION(RETTYPE, EXPRESSION, FAILED) \
  98   if (ferror (stream))                                                        \
  99     return (EXPRESSION);                                                      \
 100   else                                                                        \
 101     {                                                                         \
 102       RETTYPE ret;                                                            \
 103       CLEAR_ERRNO                                                             \
 104       CLEAR_LastError                                                         \
 105       ret = (EXPRESSION);                                                     \
 106       if (FAILED)                                                             \
 107         {                                                                     \
 108           HANDLE_ENOSPC                                                       \
 109           HANDLE_ERROR_NO_DATA                                                \
 110           ;                                                                   \
 111         }                                                                     \
 112       return ret;                                                             \
 113     }
 114
 115 #  if !REPLACE_PRINTF_POSIX /* avoid collision with printf.c */
 116 int
 117 printf (const char *format, ...)
 118 {
 119   int retval;
 120   va_list args;
 121
 122   va_start (args, format);
 123   retval = vfprintf (stdout, format, args);
 124   va_end (args);
 125
 126   return retval;
 127 }
 128 #  endif
 129
 130 #  if !REPLACE_FPRINTF_POSIX /* avoid collision with fprintf.c */
 131 int
 132 fprintf (FILE *stream, const char *format, ...)
 133 {
 134   int retval;
 135   va_list args;
 136
 137   va_start (args, format);
 138   retval = vfprintf (stream, format, args);
 139   va_end (args);
 140
 141   return retval;
 142 }
 143 #  endif
 144
 145 #  if !REPLACE_VPRINTF_POSIX /* avoid collision with vprintf.c */
 146 int
 147 vprintf (const char *format, va_list args)
 148 {
 149   return vfprintf (stdout, format, args);
 150 }
 151 #  endif
 152
 153 #  if !REPLACE_VFPRINTF_POSIX /* avoid collision with vfprintf.c */
 154 int
 155 vfprintf (FILE *stream, const char *format, va_list args)
 156 #undef vfprintf
 157 {
 158   CALL_WITH_SIGPIPE_EMULATION (int, vfprintf (stream, format, args), ret == EOF)
 159 }
 160 #  endif
 161
 162 int
 163 putchar (int c)
 164 {
 165   return fputc (c, stdout);
 166 }
 167
 168 int
 169 fputc (int c, FILE *stream)
 170 #undef fputc
 171 {
 172   CALL_WITH_SIGPIPE_EMULATION (int, fputc (c, stream), ret == EOF)
 173 }
 174
 175 int
 176 fputs (const char *string, FILE *stream)
 177 #undef fputs
 178 {
 179   CALL_WITH_SIGPIPE_EMULATION (int, fputs (string, stream), ret == EOF)
 180 }
 181
 182 int
 183 puts (const char *string)
 184 #undef puts
 185 {
 186   FILE *stream = stdout;
 187   CALL_WITH_SIGPIPE_EMULATION (int, puts (string), ret == EOF)
 188 }
 189
 190 size_t
 191 fwrite (const void *ptr, size_t s, size_t n, FILE *stream)
 192 #undef fwrite
 193 {
 194   CALL_WITH_SIGPIPE_EMULATION (size_t, fwrite (ptr, s, n, stream), ret < n)
 195 }
 196
 197 # endif
 198 #endif