wsetup.c
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上传日期:2007-04-14
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文件大小:3k
- /*-
- * Copyright (c) 1990 The Regents of the University of California.
- * Copyright (c) 1993, 1994 Chris Provenzano.
- * All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * Chris Torek.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
- #if defined(LIBC_SCCS) && !defined(lint)
- /*static char *sccsid = "from: @(#)wsetup.c 5.2 (Berkeley) 2/24/91";*/
- static char *rcsid = "$Id$";
- #endif /* LIBC_SCCS and not lint */
- #include <stdio.h>
- #include <stdlib.h>
- #include "local.h"
- /*
- * Various output routines call wsetup to be sure it is safe to write,
- * because either _flags does not include __SWR, or _buf is NULL.
- * _wsetup returns 0 if OK to write, nonzero otherwise.
- */
- __swsetup(fp)
- register FILE *fp;
- {
- /* make sure stdio is set up */
- __sinit ();
- /*
- * If we are not writing, we had better be reading and writing.
- */
- if ((fp->_flags & __SWR) == 0) {
- if ((fp->_flags & __SRW) == 0)
- return (EOF);
- if (fp->_flags & __SRD) {
- /* clobber any ungetc data */
- if (HASUB(fp))
- FREEUB(fp);
- fp->_flags &= ~(__SRD|__SEOF);
- fp->_r = 0;
- fp->_p = fp->_bf._base;
- }
- fp->_flags |= __SWR;
- }
- /*
- * Make a buffer if necessary, then set _w.
- */
- if (fp->_bf._base == NULL)
- __smakebuf(fp);
- if (fp->_flags & __SLBF) {
- /*
- * It is line buffered, so make _lbfsize be -_bufsize
- * for the putc() macro. We will change _lbfsize back
- * to 0 whenever we turn off __SWR.
- */
- fp->_w = 0;
- fp->_lbfsize = -fp->_bf._size;
- } else
- fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size;
- return (0);
- }