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 * @(#)wsetup.c 8.1 (Berkeley) 6/4/93
33 * $FreeBSD: src/lib/libc/stdio/wsetup.c,v 1.11 2009/01/08 06:38:06 das Exp $
34 */
35
36 #include <errno.h>
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; otherwise, it returns EOF and sets errno.
45 */
46 int
__swsetup(FILE * fp)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->pub._flags & __SWR) == 0) {
57 if ((fp->pub._flags & __SRW) == 0) {
58 errno = EBADF;
59 fp->pub._flags |= __SERR;
60 return (EOF);
61 }
62 if (fp->pub._flags & __SRD) {
63 /* clobber any ungetc data */
64 if (HASUB(fp))
65 FREEUB(fp);
66 fp->pub._flags &= ~(__SRD|__SEOF);
67 fp->pub._r = 0;
68 fp->pub._p = fp->_bf._base;
69 }
70 fp->pub._flags |= __SWR;
71 }
72
73 /*
74 * Make a buffer if necessary, then set _w.
75 */
76 if (fp->_bf._base == NULL)
77 __smakebuf(fp);
78 if (fp->pub._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->pub._w = 0;
85 fp->pub._lbfsize = -fp->_bf._size;
86 } else
87 fp->pub._w = fp->pub._flags & __SNBF ? 0 : fp->_bf._size;
88 return (0);
89 }
90