104 lines
3.4 KiB
C
104 lines
3.4 KiB
C
/*
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Copyright (C) 1993 Free Software Foundation
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This file is part of the GNU IO Library. This library is free
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software; you can redistribute it and/or modify it under the
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terms of the GNU General Public License as published by the
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Free Software Foundation; either version 2, or (at your option)
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any later version.
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This library 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 GNU CC; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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As a special exception, if you link this library with files
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compiled with a GNU compiler to produce an executable, this does not cause
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the resulting executable to be covered by the GNU General Public License.
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This exception does not however invalidate any other reasons why
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the executable file might be covered by the GNU General Public License. */
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/*
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* advertising materials, and other materials related to such
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* distribution and use acknowledge that the software was developed
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* by the University of California, Berkeley. The name of the
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* University may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*/
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/* Modified for GNU iostream by Per Bothner 1991, 1992. */
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#define _POSIX_SOURCE
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#include "libioP.h"
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#include <sys/types.h>
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#include <sys/stat.h>
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#ifdef __STDC__
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#include <stdlib.h>
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#endif
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/* If this function pointer is non-zero, we should call it.
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It's supposed to make sure _IO_cleanup gets called on exit.
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We call it from _IO_file_doallocate, since that is likely
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to get called by any program that does buffered I/O. */
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void (*_IO_cleanup_registration_needed)();
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/*
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* Allocate a file buffer, or switch to unbuffered I/O.
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* Per the ANSI C standard, ALL tty devices default to line buffered.
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*
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* As a side effect, we set __SOPT or __SNPT (en/dis-able fseek
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* optimisation) right after the _fstat() that finds the buffer size.
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*/
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int
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_IO_file_doallocate(fp)
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register _IO_FILE *fp;
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{
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register _IO_size_t size;
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int couldbetty;
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register char *p;
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struct stat st;
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if (_IO_cleanup_registration_needed)
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(*_IO_cleanup_registration_needed)();
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if (fp->_fileno < 0 || fp->_jumps->__stat(fp, &st) < 0)
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{
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couldbetty = 0;
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size = _IO_BUFSIZ;
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#if 0
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/* do not try to optimise fseek() */
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fp->_flags |= __SNPT;
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#endif
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}
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else
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{
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couldbetty = S_ISCHR(st.st_mode);
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#if _IO_HAVE_ST_BLKSIZE
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size = st.st_blksize <= 0 ? _IO_BUFSIZ : st.st_blksize;
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#else
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size = _IO_BUFSIZ;
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#endif
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}
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p = ALLOC_BUF(size);
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if (p == NULL)
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return EOF;
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_IO_setb(fp, p, p+size, 1);
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if (couldbetty && isatty(fp->_fileno))
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fp->_flags |= _IO_LINE_BUF;
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return 1;
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}
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