lib/stdio-write.c

   1 /* POSIX compatible FILE stream write function.
   2    Copyright (C) 2008-2011 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 Lesser 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 Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser 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 'sigpipe' is requested.  */
  24 #if GNULIB_SIGPIPE
  25
  26 /* On native Windows platforms, SIGPIPE does not exist.  When write() is
  27    called on a pipe with no readers, WriteFile() fails with error
  28    GetLastError() = ERROR_NO_DATA, and write() in consequence fails with
  29    error EINVAL.  This write() function is at the basis of the function
  30    which flushes the buffer of a FILE stream.  */
  31
  32 # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  33
  34 #  include <errno.h>
  35 #  include <signal.h>
  36 #  include <io.h>
  37
  38 #  define WIN32_LEAN_AND_MEAN  /* avoid including junk */
  39 #  include <windows.h>
  40
  41 #  define CALL_WITH_SIGPIPE_EMULATION(RETTYPE, EXPRESSION, FAILED) \
  42   if (ferror (stream))                                                        \
  43     return (EXPRESSION);                                                      \
  44   else                                                                        \
  45     {                                                                         \
  46       RETTYPE ret;                                                            \
  47       SetLastError (0);                                                       \
  48       ret = (EXPRESSION);                                                     \
  49       if (FAILED && GetLastError () == ERROR_NO_DATA && ferror (stream))      \
  50         {                                                                     \
  51           int fd = fileno (stream);                                           \
  52           if (fd >= 0                                                         \
  53               && GetFileType ((HANDLE) _get_osfhandle (fd)) == FILE_TYPE_PIPE)\
  54             {                                                                 \
  55               /* Try to raise signal SIGPIPE.  */                             \
  56               raise (SIGPIPE);                                                \
  57               /* If it is currently blocked or ignored, change errno from     \
  58                  EINVAL to EPIPE.  */                                         \
  59               errno = EPIPE;                                                  \
  60             }                                                                 \
  61         }                                                                     \
  62       return ret;                                                             \
  63     }
  64
  65 #  if !REPLACE_PRINTF_POSIX /* avoid collision with printf.c */
  66 int
  67 printf (const char *format, ...)
  68 {
  69   int retval;
  70   va_list args;
  71
  72   va_start (args, format);
  73   retval = vfprintf (stdout, format, args);
  74   va_end (args);
  75
  76   return retval;
  77 }
  78 #  endif
  79
  80 #  if !REPLACE_FPRINTF_POSIX /* avoid collision with fprintf.c */
  81 int
  82 fprintf (FILE *stream, const char *format, ...)
  83 {
  84   int retval;
  85   va_list args;
  86
  87   va_start (args, format);
  88   retval = vfprintf (stream, format, args);
  89   va_end (args);
  90
  91   return retval;
  92 }
  93 #  endif
  94
  95 #  if !REPLACE_VPRINTF_POSIX /* avoid collision with vprintf.c */
  96 int
  97 vprintf (const char *format, va_list args)
  98 {
  99   return vfprintf (stdout, format, args);
 100 }
 101 #  endif
 102
 103 #  if !REPLACE_VFPRINTF_POSIX /* avoid collision with vfprintf.c */
 104 int
 105 vfprintf (FILE *stream, const char *format, va_list args)
 106 #undef vfprintf
 107 {
 108   CALL_WITH_SIGPIPE_EMULATION (int, vfprintf (stream, format, args), ret == EOF)
 109 }
 110 #  endif
 111
 112 int
 113 putchar (int c)
 114 {
 115   return fputc (c, stdout);
 116 }
 117
 118 int
 119 fputc (int c, FILE *stream)
 120 #undef fputc
 121 {
 122   CALL_WITH_SIGPIPE_EMULATION (int, fputc (c, stream), ret == EOF)
 123 }
 124
 125 int
 126 fputs (const char *string, FILE *stream)
 127 #undef fputs
 128 {
 129   CALL_WITH_SIGPIPE_EMULATION (int, fputs (string, stream), ret == EOF)
 130 }
 131
 132 int
 133 puts (const char *string)
 134 #undef puts
 135 {
 136   FILE *stream = stdout;
 137   CALL_WITH_SIGPIPE_EMULATION (int, puts (string), ret == EOF)
 138 }
 139
 140 size_t
 141 fwrite (const void *ptr, size_t s, size_t n, FILE *stream)
 142 #undef fwrite
 143 {
 144   CALL_WITH_SIGPIPE_EMULATION (size_t, fwrite (ptr, s, n, stream), ret < n)
 145 }
 146
 147 # endif
 148 #endif