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. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #if defined(LIBC_SCCS) && !defined(lint) 34 static char rcsid[] = "$OpenBSD: wsetup.c,v 1.6 2004/09/28 18:12:44 otto Exp $"; 35 #endif /* LIBC_SCCS and not lint */ 36 37 #include <stdio.h> 38 #include <stdlib.h> 39 #include "local.h" 40 41 /* 42 * Various output routines call wsetup to be sure it is safe to write, 43 * because either _flags does not include __SWR, or _buf is NULL. 44 * _wsetup returns 0 if OK to write, nonzero otherwise. 45 */ 46 int 47 __swsetup(FILE *fp) 48 { 49 /* make sure stdio is set up */ 50 if (!__sdidinit) 51 __sinit(); 52 53 /* 54 * If we are not writing, we had better be reading and writing. 55 */ 56 if ((fp->_flags & __SWR) == 0) { 57 if ((fp->_flags & __SRW) == 0) 58 return (EOF); 59 if (fp->_flags & __SRD) { 60 /* clobber any ungetc data */ 61 if (HASUB(fp)) 62 FREEUB(fp); 63 fp->_flags &= ~(__SRD|__SEOF); 64 fp->_r = 0; 65 fp->_p = fp->_bf._base; 66 } 67 fp->_flags |= __SWR; 68 } 69 70 /* 71 * Make a buffer if necessary, then set _w. 72 */ 73 if (fp->_bf._base == NULL) { 74 if ((fp->_flags & (__SSTR | __SALC)) == __SSTR) 75 return (EOF); 76 __smakebuf(fp); 77 } 78 if (fp->_flags & __SLBF) { 79 /* 80 * It is line buffered, so make _lbfsize be -_bufsize 81 * for the putc() macro. We will change _lbfsize back 82 * to 0 whenever we turn off __SWR. 83 */ 84 fp->_w = 0; 85 fp->_lbfsize = -fp->_bf._size; 86 } else 87 fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size; 88 return (0); 89 } 90