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1 | /*- |
2 | * Copyright (c) 1990 The Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * This code is derived from software contributed to Berkeley by | |
6 | * Chris Torek. | |
7 | * | |
8 | * %sccs.include.redist.c% | |
9 | */ | |
10 | ||
11 | #if defined(LIBC_SCCS) && !defined(lint) | |
cb631443 | 12 | static char sccsid[] = "@(#)wsetup.c 5.2 (Berkeley) %G%"; |
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13 | #endif /* LIBC_SCCS and not lint */ |
14 | ||
15 | #include <stdio.h> | |
cb631443 | 16 | #include <stdlib.h> |
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17 | #include "local.h" |
18 | ||
19 | /* | |
20 | * Various output routines call wsetup to be sure it is safe to write, | |
21 | * because either _flags does not include __SWR, or _buf is NULL. | |
22 | * _wsetup returns 0 if OK to write, nonzero otherwise. | |
23 | */ | |
24 | __swsetup(fp) | |
25 | register FILE *fp; | |
26 | { | |
27 | /* make sure stdio is set up */ | |
28 | if (!__sdidinit) | |
29 | __sinit(); | |
30 | ||
31 | /* | |
32 | * If we are not writing, we had better be reading and writing. | |
33 | */ | |
34 | if ((fp->_flags & __SWR) == 0) { | |
35 | if ((fp->_flags & __SRW) == 0) | |
36 | return (EOF); | |
37 | if (fp->_flags & __SRD) { | |
38 | /* clobber any ungetc data */ | |
39 | if (HASUB(fp)) | |
40 | FREEUB(fp); | |
41 | fp->_flags &= ~(__SRD|__SEOF); | |
42 | fp->_r = 0; | |
43 | fp->_p = fp->_bf._base; | |
44 | } | |
45 | fp->_flags |= __SWR; | |
46 | } | |
47 | ||
48 | /* | |
49 | * Make a buffer if necessary, then set _w. | |
50 | */ | |
51 | if (fp->_bf._base == NULL) | |
52 | __smakebuf(fp); | |
53 | if (fp->_flags & __SLBF) { | |
54 | /* | |
55 | * It is line buffered, so make _lbfsize be -_bufsize | |
56 | * for the putc() macro. We will change _lbfsize back | |
57 | * to 0 whenever we turn off __SWR. | |
58 | */ | |
59 | fp->_w = 0; | |
60 | fp->_lbfsize = -fp->_bf._size; | |
61 | } else | |
62 | fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size; | |
63 | return (0); | |
64 | } |