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/* Retrieve information about a FILE stream.
Copyright (C) 2007 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
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.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
/* Specification. */
#include "freadahead.h"
size_t
freadahead (FILE *fp)
{
#if defined _IO_ferror_unlocked /* GNU libc, BeOS */
if (fp->_IO_write_ptr > fp->_IO_write_base)
return 0;
return fp->_IO_read_end - fp->_IO_read_ptr;
#elif defined __sferror /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */
if ((fp->_flags & __SWR) != 0 || fp->_r < 0)
return 0;
return fp->_r;
#elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, mingw */
# if defined __sun && defined _LP64 /* Solaris/{SPARC,AMD64} 64-bit */
# define fp_ ((struct { unsigned char *_ptr; \
unsigned char *_base; \
unsigned char *_end; \
long _cnt; \
int _file; \
unsigned int _flag; \
} *) fp)
if ((fp_->_flag & _IOWRT) != 0)
return 0;
return fp_->_cnt;
# else
if ((fp->_flag & _IOWRT) != 0)
return 0;
return fp->_cnt;
# endif
#elif defined __UCLIBC__ /* uClibc */
# ifdef __STDIO_BUFFERS
if (fp->__modeflags & __FLAG_WRITING)
return 0;
return fp->__bufread - fp->__bufpos;
# else
return 0;
# endif
#elif defined __QNX__ /* QNX */
if ((fp->_Mode & _MWRITE) != 0)
return 0;
/* fp->_Buf <= fp->_Next <= fp->_Rend */
return fp->_Rend - fp->_Next;
#else
#error "Please port gnulib freadahead.c to your platform! Look at the definition of fflush, fread on your system, then report this to bug-gnulib."
#endif
}
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