freadable.c 1.87 KB
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/* Retrieve information about a FILE stream.
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   Copyright (C) 2007-2010 Free Software Foundation, Inc.
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   This program is free software: you can redistribute it and/or modify
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   it under the terms of the GNU General Public License as published by
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   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
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   This program 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 General Public License for more details.

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   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
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#include <config.h>

/* Specification.  */
#include "freadable.h"

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#include "stdio-impl.h"

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bool
freadable (FILE *fp)
{
  /* Most systems provide FILE as a struct and the necessary bitmask in
     <stdio.h>, because they need it for implementing getc() and putc() as
     fast macros.  */
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#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
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  return (fp->_flags & _IO_NO_READS) == 0;
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#elif defined __sferror || defined __DragonFly__ /* FreeBSD, NetBSD, OpenBSD, DragonFly, MacOS X, Cygwin */
  return (fp_->_flags & (__SRW | __SRD)) != 0;
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#elif defined __EMX__               /* emx+gcc */
  return (fp->_flags & (_IORW | _IOREAD)) != 0;
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#elif defined _IOERR                /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, mingw */
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  return (fp->_flag & (_IORW | _IOREAD)) != 0;
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#elif defined __QNX__               /* QNX */
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  return (fp->_Mode & 0x1 /* _MOPENR */) != 0;
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#elif defined __MINT__              /* Atari FreeMiNT */
  return fp->__mode.__read;
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#else
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 #error "Please port gnulib freadable.c to your platform! Look at the definition of fopen, fdopen on your system, then report this to bug-gnulib."
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#endif
}