1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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 <errno.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include "local.h" 39 40 /* 41 * Various output routines call wsetup to be sure it is safe to write, 42 * because either _flags does not include __SWR, or _buf is NULL. 43 * _wsetup returns 0 if OK to write; otherwise, it returns EOF and sets errno. 44 */ 45 int 46 __swsetup(FILE *fp) 47 { 48 /* make sure stdio is set up */ 49 if (!__sdidinit) 50 __sinit(); 51 52 /* 53 * If we are not writing, we had better be reading and writing. 54 */ 55 if ((fp->_flags & __SWR) == 0) { 56 if ((fp->_flags & __SRW) == 0) { 57 errno = EBADF; 58 fp->_flags |= __SERR; 59 return (EOF); 60 } 61 if (fp->_flags & __SRD) { 62 /* clobber any ungetc data */ 63 if (HASUB(fp)) 64 FREEUB(fp); 65 fp->_flags &= ~(__SRD|__SEOF); 66 fp->_r = 0; 67 fp->_p = fp->_bf._base; 68 } 69 fp->_flags |= __SWR; 70 } 71 72 /* 73 * Make a buffer if necessary, then set _w. 74 */ 75 if (fp->_bf._base == NULL) 76 __smakebuf(fp); 77 if (fp->_flags & __SLBF) { 78 /* 79 * It is line buffered, so make _lbfsize be -_bufsize 80 * for the putc() macro. We will change _lbfsize back 81 * to 0 whenever we turn off __SWR. 82 */ 83 fp->_w = 0; 84 fp->_lbfsize = -fp->_bf._size; 85 } else 86 fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size; 87 return (0); 88 } 89