1 /* $OpenBSD: wsetup.c,v 1.7 2005/08/08 08:05:36 espie Exp $ */ 2 /*- 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Chris Torek. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include "local.h" 37 38 /* 39 * Various output routines call wsetup to be sure it is safe to write, 40 * because either _flags does not include __SWR, or _buf is NULL. 41 * _wsetup returns 0 if OK to write, nonzero otherwise. 42 */ 43 int 44 __swsetup(FILE *fp) 45 { 46 /* make sure stdio is set up */ 47 if (!__sdidinit) 48 __sinit(); 49 50 /* 51 * If we are not writing, we had better be reading and writing. 52 */ 53 if ((fp->_flags & __SWR) == 0) { 54 if ((fp->_flags & __SRW) == 0) 55 return (EOF); 56 if (fp->_flags & __SRD) { 57 /* clobber any ungetc data */ 58 if (HASUB(fp)) 59 FREEUB(fp); 60 fp->_flags &= ~(__SRD|__SEOF); 61 fp->_r = 0; 62 fp->_p = fp->_bf._base; 63 } 64 fp->_flags |= __SWR; 65 } 66 67 /* 68 * Make a buffer if necessary, then set _w. 69 */ 70 if (fp->_bf._base == NULL) { 71 if ((fp->_flags & (__SSTR | __SALC)) == __SSTR) 72 return (EOF); 73 __smakebuf(fp); 74 } 75 if (fp->_flags & __SLBF) { 76 /* 77 * It is line buffered, so make _lbfsize be -_bufsize 78 * for the putc() macro. We will change _lbfsize back 79 * to 0 whenever we turn off __SWR. 80 */ 81 fp->_w = 0; 82 fp->_lbfsize = -fp->_bf._size; 83 } else 84 fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size; 85 return (0); 86 } 87
