1/* $NetBSD: wsetup.c,v 1.10 2003/01/18 11:30:00 thorpej Exp $ */ 2 3/*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35#include <sys/cdefs.h> 36#if defined(LIBC_SCCS) && !defined(lint) 37#if 0 38static char sccsid[] = "@(#)wsetup.c 8.1 (Berkeley) 6/4/93"; 39#else 40__RCSID("$NetBSD: wsetup.c,v 1.10 2003/01/18 11:30:00 thorpej Exp $"); 41#endif 42#endif /* LIBC_SCCS and not lint */ 43 44#include <assert.h> 45#include <errno.h> 46#include <stdio.h> 47#include <stdlib.h> 48#include "reentrant.h" 49#include "local.h" 50 51/* 52 * Various output routines call wsetup to be sure it is safe to write, 53 * because either _flags does not include __SWR, or _buf is NULL. 54 * _wsetup returns 0 if OK to write, nonzero otherwise. 55 */ 56int 57__swsetup(fp) 58 FILE *fp; 59{ 60 61 _DIAGASSERT(fp != NULL); 62 63 /* make sure stdio is set up */ 64 if (!__sdidinit) 65 __sinit(); 66 67 /* 68 * If we are not writing, we had better be reading and writing. 69 */ 70 if ((fp->_flags & __SWR) == 0) { 71 if ((fp->_flags & __SRW) == 0) 72 return (EOF); 73 if (fp->_flags & __SRD) { 74 /* clobber any ungetc data */ 75 if (HASUB(fp)) 76 FREEUB(fp); 77 fp->_flags &= ~(__SRD|__SEOF); 78 fp->_r = 0; 79 fp->_p = fp->_bf._base; 80 } 81 fp->_flags |= __SWR; 82 } 83 84 /* 85 * Make a buffer if necessary, then set _w. 86 */ 87 if (fp->_bf._base == NULL) 88 __smakebuf(fp); 89 if (fp->_flags & __SLBF) { 90 /* 91 * It is line buffered, so make _lbfsize be -_bufsize 92 * for the putc() macro. We will change _lbfsize back 93 * to 0 whenever we turn off __SWR. 94 */ 95 fp->_w = 0; 96 fp->_lbfsize = -fp->_bf._size; 97 } else 98 fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size; 99 return (0); 100} 101