1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Chris Torek. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)wsetup.c 8.1 (Berkeley) 6/4/93 37 * $FreeBSD: src/lib/libc/stdio/wsetup.c,v 1.6 1999/08/28 00:01:22 peter Exp $ 38 * $DragonFly: src/lib/libc/stdio/wsetup.c,v 1.4 2004/06/07 20:35:41 hmp Exp $ 39 */ 40 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include "local.h" 44 45 /* 46 * Various output routines call wsetup to be sure it is safe to write, 47 * because either _flags does not include __SWR, or _buf is NULL. 48 * _wsetup returns 0 if OK to write, nonzero otherwise. 49 */ 50 int 51 __swsetup(FILE *fp) 52 { 53 /* make sure stdio is set up */ 54 if (!__sdidinit) 55 __sinit(); 56 57 /* 58 * If we are not writing, we had better be reading and writing. 59 */ 60 if ((fp->_flags & __SWR) == 0) { 61 if ((fp->_flags & __SRW) == 0) 62 return (EOF); 63 if (fp->_flags & __SRD) { 64 /* clobber any ungetc data */ 65 if (HASUB(fp)) 66 FREEUB(fp); 67 fp->_flags &= ~(__SRD|__SEOF); 68 fp->_r = 0; 69 fp->_p = fp->_bf._base; 70 } 71 fp->_flags |= __SWR; 72 } 73 74 /* 75 * Make a buffer if necessary, then set _w. 76 */ 77 if (fp->_bf._base == NULL) 78 __smakebuf(fp); 79 if (fp->_flags & __SLBF) { 80 /* 81 * It is line buffered, so make _lbfsize be -_bufsize 82 * for the putc() macro. We will change _lbfsize back 83 * to 0 whenever we turn off __SWR. 84 */ 85 fp->_w = 0; 86 fp->_lbfsize = -fp->_bf._size; 87 } else 88 fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size; 89 return (0); 90 } 91