1 /* $NetBSD: wsetup.c,v 1.9 1999/09/20 04:39:35 lukem 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)wsetup.c 8.1 (Berkeley) 6/4/93"; 43 #else 44 __RCSID("$NetBSD: wsetup.c,v 1.9 1999/09/20 04:39:35 lukem Exp $"); 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include <assert.h> 49 #include <errno.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include "local.h" 53 54 /* 55 * Various output routines call wsetup to be sure it is safe to write, 56 * because either _flags does not include __SWR, or _buf is NULL. 57 * _wsetup returns 0 if OK to write, nonzero otherwise. 58 */ 59 int 60 __swsetup(fp) 61 FILE *fp; 62 { 63 64 _DIAGASSERT(fp != NULL); 65 66 /* make sure stdio is set up */ 67 if (!__sdidinit) 68 __sinit(); 69 70 /* 71 * If we are not writing, we had better be reading and writing. 72 */ 73 if ((fp->_flags & __SWR) == 0) { 74 if ((fp->_flags & __SRW) == 0) 75 return (EOF); 76 if (fp->_flags & __SRD) { 77 /* clobber any ungetc data */ 78 if (HASUB(fp)) 79 FREEUB(fp); 80 fp->_flags &= ~(__SRD|__SEOF); 81 fp->_r = 0; 82 fp->_p = fp->_bf._base; 83 } 84 fp->_flags |= __SWR; 85 } 86 87 /* 88 * Make a buffer if necessary, then set _w. 89 */ 90 if (fp->_bf._base == NULL) 91 __smakebuf(fp); 92 if (fp->_flags & __SLBF) { 93 /* 94 * It is line buffered, so make _lbfsize be -_bufsize 95 * for the putc() macro. We will change _lbfsize back 96 * to 0 whenever we turn off __SWR. 97 */ 98 fp->_w = 0; 99 fp->_lbfsize = -fp->_bf._size; 100 } else 101 fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size; 102 return (0); 103 } 104