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 sccsid[] = "@(#)wsetup.c 8.1 (Berkeley) 6/4/93"; 35 #endif /* LIBC_SCCS and not lint */ 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include <errno.h> 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include "local.h" 43 44 /* 45 * Various output routines call wsetup to be sure it is safe to write, 46 * because either _flags does not include __SWR, or _buf is NULL. 47 * _wsetup returns 0 if OK to write; otherwise, it returns EOF and sets errno. 48 */ 49 int 50 __swsetup(FILE *fp) 51 { 52 /* make sure stdio is set up */ 53 if (!__sdidinit) 54 __sinit(); 55 56 /* 57 * If we are not writing, we had better be reading and writing. 58 */ 59 if ((fp->_flags & __SWR) == 0) { 60 if ((fp->_flags & __SRW) == 0) { 61 errno = EBADF; 62 fp->_flags |= __SERR; 63 return (EOF); 64 } 65 if (fp->_flags & __SRD) { 66 /* clobber any ungetc data */ 67 if (HASUB(fp)) 68 FREEUB(fp); 69 fp->_flags &= ~(__SRD|__SEOF); 70 fp->_r = 0; 71 fp->_p = fp->_bf._base; 72 } 73 fp->_flags |= __SWR; 74 } 75 76 /* 77 * Make a buffer if necessary, then set _w. 78 */ 79 if (fp->_bf._base == NULL) 80 __smakebuf(fp); 81 if (fp->_flags & __SLBF) { 82 /* 83 * It is line buffered, so make _lbfsize be -_bufsize 84 * for the putc() macro. We will change _lbfsize back 85 * to 0 whenever we turn off __SWR. 86 */ 87 fp->_w = 0; 88 fp->_lbfsize = -fp->_bf._size; 89 } else 90 fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size; 91 return (0); 92 } 93