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86 lines
3.0 KiB
C
86 lines
3.0 KiB
C
/* Retrieve information about a FILE stream.
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Copyright (C) 2007-2009 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
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include <config.h>
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/* Specification. */
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#include "freadahead.h"
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#include <stdlib.h>
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#include "stdio-impl.h"
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size_t
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freadahead (FILE *fp)
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{
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#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
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if (fp->_IO_write_ptr > fp->_IO_write_base)
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return 0;
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return (fp->_IO_read_end - fp->_IO_read_ptr)
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+ (fp->_flags & _IO_IN_BACKUP ? fp->_IO_save_end - fp->_IO_save_base :
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0);
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#elif defined __sferror || defined __DragonFly__ /* FreeBSD, NetBSD, OpenBSD, DragonFly, MacOS X, Cygwin */
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if ((fp_->_flags & __SWR) != 0 || fp_->_r < 0)
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return 0;
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# if defined __DragonFly__
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return __sreadahead (fp);
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# else
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return fp_->_r
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+ (HASUB (fp) ? fp_->_ur : 0);
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# endif
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#elif defined __EMX__ /* emx+gcc */
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if ((fp->_flags & _IOWRT) != 0)
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return 0;
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/* Note: fp->_ungetc_count > 0 implies fp->_rcount <= 0,
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fp->_ungetc_count = 0 implies fp->_rcount >= 0. */
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/* equivalent to
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(fp->_ungetc_count == 0 ? fp->_rcount : fp->_ungetc_count - fp->_rcount) */
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return (fp->_rcount > 0 ? fp->_rcount : fp->_ungetc_count - fp->_rcount);
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#elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, mingw */
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if ((fp_->_flag & _IOWRT) != 0)
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return 0;
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return fp_->_cnt;
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#elif defined __UCLIBC__ /* uClibc */
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# ifdef __STDIO_BUFFERS
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if (fp->__modeflags & __FLAG_WRITING)
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return 0;
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return (fp->__bufread - fp->__bufpos)
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+ (fp->__modeflags & __FLAG_UNGOT ? 1 : 0);
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# else
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return 0;
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# endif
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#elif defined __QNX__ /* QNX */
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if ((fp->_Mode & 0x2000 /* _MWRITE */) != 0)
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return 0;
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/* fp->_Buf <= fp->_Next <= fp->_Rend,
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and fp->_Rend may be overridden by fp->_Rsave. */
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return ((fp->_Rsave ? fp->_Rsave : fp->_Rend) - fp->_Next)
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+ (fp->_Mode & 0x4000 /* _MBYTE */
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? (fp->_Back + sizeof (fp->_Back)) - fp->_Rback
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: 0);
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#elif defined __MINT__ /* Atari FreeMiNT */
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if (!fp->__mode.__read)
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return 0;
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return (fp->__pushed_back
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? fp->__get_limit - fp->__pushback_bufp + 1
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: fp->__get_limit - fp->__bufp);
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#elif defined SLOW_BUT_NO_HACKS /* users can define this */
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abort ();
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return 0;
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#else
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#error "Please port gnulib freadahead.c to your platform! Look at the definition of fflush, fread, ungetc on your system, then report this to bug-gnulib."
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#endif
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}
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