1 /* No user fns here. Pesch 15apr92. */
2
3 /*
4 * Copyright (c) 1990, 2007 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms are permitted
8 * provided that the above copyright notice and this paragraph are
9 * duplicated in all such forms and that any documentation,
10 * and/or other materials related to such
11 * distribution and use acknowledge that the software was developed
12 * by the University of California, Berkeley. The name of the
13 * University may not be used to endorse or promote products derived
14 * from this software without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
18 */
19
20 #define _DEFAULT_SOURCE
21 #include <_ansi.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <errno.h>
25 #include "local.h"
26
27 /*
28 * Various output routines call wsetup to be sure it is safe to write,
29 * because either _flags does not include __SWR, or _buf is NULL.
30 * _wsetup returns 0 if OK to write, nonzero and set errno otherwise.
31 */
32
33 int
_swsetup(register FILE * fp)34 _swsetup (
35 register FILE * fp)
36 {
37 /* Make sure stdio is set up. */
38
39 CHECK_INIT (_REENT, fp);
40
41 /*
42 * If we are not writing, we had better be reading and writing.
43 */
44
45 if ((fp->_flags & __SWR) == 0)
46 {
47 if ((fp->_flags & __SRW) == 0)
48 {
49 _REENT_ERRNO(ptr) = EBADF;
50 fp->_flags |= __SERR;
51 return EOF;
52 }
53 if (fp->_flags & __SRD)
54 {
55 /* clobber any ungetc data */
56 if (HASUB (fp))
57 FREEUB (ptr, fp);
58 fp->_flags &= ~(__SRD | __SEOF);
59 fp->_r = 0;
60 fp->_p = fp->_bf._base;
61 }
62 fp->_flags |= __SWR;
63 }
64
65 /*
66 * Make a buffer if necessary, then set _w.
67 * A string I/O file should not explicitly allocate a buffer
68 * unless asprintf is being used.
69 */
70 if (fp->_bf._base == NULL
71 && (!(fp->_flags & __SSTR) || (fp->_flags & __SMBF)))
72 _smakebuf ( fp);
73
74 if (fp->_flags & __SLBF)
75 {
76 /*
77 * It is line buffered, so make _lbfsize be -_bufsize
78 * for the putc() macro. We will change _lbfsize back
79 * to 0 whenever we turn off __SWR.
80 */
81 fp->_w = 0;
82 fp->_lbfsize = -fp->_bf._size;
83 }
84 else
85 fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size;
86
87 if (!fp->_bf._base && (fp->_flags & __SMBF))
88 {
89 /* __smakebuf_r set errno, but not flag */
90 fp->_flags |= __SERR;
91 return EOF;
92 }
93 return 0;
94 }
95
