lib/fbufmode.c

   1 /* Retrieve information about a FILE stream.
   2    Copyright (C) 2007-2019 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 #include <config.h>
  18
  19 /* Specification.  */
  20 #include "fbufmode.h"
  21
  22 #if HAVE___FLBF
  23 # include <stdio_ext.h>
  24 #endif
  25
  26 #include "stdio-impl.h"
  27
  28 int
  29 fbufmode (FILE *fp)
  30 {
  31   /* Most systems provide FILE as a struct and the necessary bitmask in
  32      <stdio.h>, because they need it for implementing getc() and putc() as
  33      fast macros.  */
  34 #if defined _IO_EOF_SEEN || defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1
  35   /* GNU libc, BeOS, Haiku, Linux libc5 */
  36 # if HAVE___FLBF                    /* glibc >= 2.2 */
  37   if (__flbf (fp))
  38     return _IOLBF;
  39 # else
  40   if (fp->_flags & _IO_LINE_BUF)
  41     return _IOLBF;
  42 # endif
  43   if (fp->_flags & _IO_UNBUFFERED)
  44     return _IONBF;
  45   return _IOFBF;
  46 #elif defined __sferror || defined __DragonFly__ || defined __ANDROID__
  47   /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
  48   if (fp_->_flags & __SLBF)
  49     return _IOLBF;
  50   if (fp_->_flags & __SNBF)
  51     return _IONBF;
  52   return _IOFBF;
  53 #elif defined __EMX__               /* emx+gcc */
  54   return fp->_flags & (_IOLBF | _IONBF | _IOFBF);
  55 #elif defined __minix               /* Minix */
  56   return fp->_flags & (_IOLBF | _IONBF | _IOFBF);
  57 #elif defined _IOERR                /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, mingw, MSVC, NonStop Kernel, OpenVMS */
  58 # if defined WINDOWS_OPAQUE_FILE
  59   if (fp_->_flag & 0x100)
  60     return _IOFBF; /* Impossible to distinguish _IOFBF and _IOLBF.  */
  61   else
  62     return _IONBF;
  63 # else
  64 #  if HAVE___FLBF                   /* Solaris >= 7 */
  65   if (__flbf (fp))
  66     return _IOLBF;
  67 #  else
  68   if (fp_->_flag & _IOLBF)
  69     return _IOLBF;
  70 #  endif
  71   if (fp_->_flag & _IONBF)
  72     return _IONBF;
  73   return _IOFBF;
  74 # endif
  75 #elif defined __UCLIBC__            /* uClibc */
  76   if (fp->__modeflags & __FLAG_LBF)
  77     return _IOLBF;
  78   if (fp->__modeflags & __FLAG_NBF)
  79     return _IONBF;
  80   return _IOFBF;
  81 #elif defined __QNX__               /* QNX */
  82   if (fp->_Mode & 0x400 /* _MLBF */)
  83     return _IOLBF;
  84   if (fp->_Mode & 0x800 /* _MNBF */)
  85     return _IONBF;
  86   return _IOFBF;
  87 #elif defined __MINT__              /* Atari FreeMiNT */
  88   if (fp->__linebuf)
  89     return _IOLBF;
  90   return (fp->__bufsize > 0 ? _IOFBF : _IONBF);
  91 #elif HAVE___FLBF && HAVE___FBUFSIZE /* musl libc */
  92   if (__flbf (fp))
  93     return _IOLBF;
  94   return (__fbufsize (fp) > 0 ? _IOFBF : _IONBF);
  95 #elif defined EPLAN9                /* Plan9 */
  96   if (fp->flags & 2 /* LINEBUF */)
  97     return _IOLBF;
  98   if (fp->bufl)
  99     return _IOFBF;
 100   return _IONBF;
 101 #else
 102 # error "Please port gnulib fbufmode.c to your platform! Look at the setvbuf implementation."
 103 #endif
 104 }