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 #if defined(LIBC_SCCS) && !defined(lint) 36 static char sccsid[] = "@(#)wsetup.c 8.1 (Berkeley) 6/4/93"; 37 #endif /* LIBC_SCCS and not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <errno.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include "local.h" 45 46 /* 47 * Various output routines call wsetup to be sure it is safe to write, 48 * because either _flags does not include __SWR, or _buf is NULL. 49 * _wsetup returns 0 if OK to write; otherwise, it returns EOF and sets errno. 50 */ 51 int 52 __swsetup(FILE *fp) 53 { 54 /* make sure stdio is set up */ 55 if (!__sdidinit) 56 __sinit(); 57 58 /* 59 * If we are not writing, we had better be reading and writing. 60 */ 61 if ((fp->_flags & __SWR) == 0) { 62 if ((fp->_flags & __SRW) == 0) { 63 errno = EBADF; 64 fp->_flags |= __SERR; 65 return (EOF); 66 } 67 if (fp->_flags & __SRD) { 68 /* clobber any ungetc data */ 69 if (HASUB(fp)) 70 FREEUB(fp); 71 fp->_flags &= ~(__SRD|__SEOF); 72 fp->_r = 0; 73 fp->_p = fp->_bf._base; 74 } 75 fp->_flags |= __SWR; 76 } 77 78 /* 79 * Make a buffer if necessary, then set _w. 80 */ 81 if (fp->_bf._base == NULL) 82 __smakebuf(fp); 83 if (fp->_flags & __SLBF) { 84 /* 85 * It is line buffered, so make _lbfsize be -_bufsize 86 * for the putc() macro. We will change _lbfsize back 87 * to 0 whenever we turn off __SWR. 88 */ 89 fp->_w = 0; 90 fp->_lbfsize = -fp->_bf._size; 91 } else 92 fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size; 93 return (0); 94 } 95