1 /*
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms are permitted
6 * provided that the above copyright notice and this paragraph are
7 * duplicated in all such forms and that any documentation,
8 * and/or other materials related to such
9 * distribution and use acknowledge that the software was developed
10 * by the University of California, Berkeley. The name of the
11 * University may not be used to endorse or promote products derived
12 * from this software without specific prior written permission.
13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16 */
17 /* No user fns here. Pesch 15apr92. */
18
19 #if defined(LIBC_SCCS) && !defined(lint)
20 static char sccsid[] = "%W% (Berkeley) %G%";
21 #endif /* LIBC_SCCS and not lint */
22
23 #define _DEFAULT_SOURCE
24 #include <_ansi.h>
25 #include <stdio.h>
26 #include <errno.h>
27 #include "local.h"
28 #include "fvwrite.h"
29
30 /*
31 * Write the given character into the (probably full) buffer for
32 * the given file. Flush the buffer out if it is or becomes full,
33 * or if c=='\n' and the file is line buffered.
34 */
35
36 int
_swbuf(register int c,register FILE * fp)37 _swbuf (
38 register int c,
39 register FILE *fp)
40 {
41 register int n;
42
43 /* Ensure stdio has been initialized. */
44
45 CHECK_INIT (ptr, fp);
46
47 /*
48 * In case we cannot write, or longjmp takes us out early,
49 * make sure _w is 0 (if fully- or un-buffered) or -_bf._size
50 * (if line buffered) so that we will get called again.
51 * If we did not do this, a sufficient number of putc()
52 * calls might wrap _w from negative to positive.
53 */
54
55 fp->_w = fp->_lbfsize;
56 if (cantwrite (ptr, fp))
57 return EOF;
58 c = (unsigned char) c;
59
60 if (ORIENT (fp, -1) != -1)
61 return EOF;
62
63 /*
64 * If it is completely full, flush it out. Then, in any case,
65 * stuff c into the buffer. If this causes the buffer to fill
66 * completely, or if c is '\n' and the file is line buffered,
67 * flush it (perhaps a second time). The second flush will always
68 * happen on unbuffered streams, where _bf._size==1; fflush()
69 * guarantees that putc() will always call wbuf() by setting _w
70 * to 0, so we need not do anything else.
71 */
72
73 n = fp->_p - fp->_bf._base;
74 if (n >= fp->_bf._size)
75 {
76 if (fflush ( fp))
77 return EOF;
78 n = 0;
79 }
80 fp->_w--;
81 *fp->_p++ = c;
82 if (++n == fp->_bf._size || (fp->_flags & __SLBF && c == '\n'))
83 if (fflush ( fp))
84 return EOF;
85 return c;
86 }
87
88 /* This function isn't any longer declared in stdio.h, but it's
89 required for backward compatibility with applications built against
90 earlier dynamically built newlib libraries. */
91 int
__swbuf(register int c,register FILE * fp)92 __swbuf (register int c,
93 register FILE *fp)
94 {
95 return _swbuf ( c, fp);
96 }
97
