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 | * 4. 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[] = "@(#)refill.c␉8.1 (Berkeley) 6/4/93";␊ |
35 | #endif /* LIBC_SCCS and not lint */␊ |
36 | #include <sys/cdefs.h>␊ |
37 | __FBSDID("$FreeBSD: src/lib/libc/stdio/refill.c,v 1.20 2008/04/17 22:17:54 jhb Exp $");␊ |
38 | ␊ |
39 | #include "namespace.h"␊ |
40 | #include <errno.h>␊ |
41 | #include <stdio.h>␊ |
42 | #include <stdlib.h>␊ |
43 | #include "un-namespace.h"␊ |
44 | ␊ |
45 | ␊ |
46 | #include "local.h"␊ |
47 | ␊ |
48 | static int lflush(FILE *);␊ |
49 | ␊ |
50 | static int␊ |
51 | lflush(FILE *fp)␊ |
52 | {␊ |
53 | ␉int␉ret = 0;␊ |
54 | ␊ |
55 | ␉if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR)) {␊ |
56 | ␉␉ret = __sflush(fp);␊ |
57 | ␉}␊ |
58 | ␉return (ret);␊ |
59 | }␊ |
60 | ␊ |
61 | /*␊ |
62 | * Refill a stdio buffer.␊ |
63 | * Return EOF on eof or error, 0 otherwise.␊ |
64 | */␊ |
65 | __private_extern__ int␊ |
66 | __srefill0(FILE *fp)␊ |
67 | {␊ |
68 | ␊ |
69 | ␉/* make sure stdio is set up */␊ |
70 | ␉if (!__sdidinit)␊ |
71 | ␉␉__sinit();␊ |
72 | ␊ |
73 | ␉ORIENT(fp, -1);␊ |
74 | ␊ |
75 | ␉fp->_r = 0;␉␉/* largely a convenience for callers */␊ |
76 | ␊ |
77 | ␉/* SysV does not make this test; take it out for compatibility */␊ |
78 | ␉if (fp->_flags & __SEOF)␊ |
79 | ␉␉return (EOF);␊ |
80 | ␊ |
81 | ␉/* if not already reading, have to be reading and writing */␊ |
82 | ␉if ((fp->_flags & __SRD) == 0) {␊ |
83 | ␉␉if ((fp->_flags & __SRW) == 0) {␊ |
84 | ␉␉␉errno = EBADF;␊ |
85 | ␉␉␉fp->_flags |= __SERR;␊ |
86 | ␉␉␉return (EOF);␊ |
87 | ␉␉}␊ |
88 | ␉␉/* switch to reading */␊ |
89 | ␉␉if (fp->_flags & __SWR) {␊ |
90 | ␉␉␉if (__sflush(fp))␊ |
91 | ␉␉␉␉return (EOF);␊ |
92 | ␉␉␉fp->_flags &= ~__SWR;␊ |
93 | ␉␉␉fp->_w = 0;␊ |
94 | ␉␉␉fp->_lbfsize = 0;␊ |
95 | ␉␉}␊ |
96 | ␉␉fp->_flags |= __SRD;␊ |
97 | ␉} else {␊ |
98 | ␉␉/*␊ |
99 | ␉␉ * We were reading. If there is an ungetc buffer,␊ |
100 | ␉␉ * we must have been reading from that. Drop it,␊ |
101 | ␉␉ * restoring the previous buffer (if any). If there␊ |
102 | ␉␉ * is anything in that buffer, return.␊ |
103 | ␉␉ */␊ |
104 | ␉␉if (HASUB(fp)) {␊ |
105 | ␉␉␉FREEUB(fp);␊ |
106 | ␉␉␉if ((fp->_r = fp->_ur) != 0) {␊ |
107 | ␉␉␉␉fp->_p = fp->_up;␊ |
108 | ␉␉␉␉return (0);␊ |
109 | ␉␉␉}␊ |
110 | ␉␉}␊ |
111 | ␉}␊ |
112 | ␊ |
113 | ␉if (fp->_bf._base == NULL)␊ |
114 | ␉␉__smakebuf(fp);␊ |
115 | ␊ |
116 | ␉/*␊ |
117 | ␉ * Before reading from a line buffered or unbuffered file,␊ |
118 | ␉ * flush all line buffered output files, per the ANSI C␊ |
119 | ␉ * standard.␊ |
120 | ␉ */␊ |
121 | ␉if (fp->_flags & (__SLBF|__SNBF)) {␊ |
122 | ␉␉/* Ignore this file in _fwalk to avoid potential deadlock. */␊ |
123 | ␉␉fp->_flags |= __SIGN;␊ |
124 | ␉␉(void) _fwalk(lflush);␊ |
125 | ␉␉fp->_flags &= ~__SIGN;␊ |
126 | ␊ |
127 | ␉␉/* Now flush this file without locking it. */␊ |
128 | ␉␉if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR))␊ |
129 | ␉␉␉__sflush(fp);␊ |
130 | ␉}␊ |
131 | ␉return (1);␊ |
132 | }␊ |
133 | ␊ |
134 | __private_extern__ int␊ |
135 | __srefill1(FILE *fp)␊ |
136 | {␊ |
137 | ␊ |
138 | ␉fp->_p = fp->_bf._base;␊ |
139 | ␉fp->_r = _sread(fp, (char *)fp->_p, fp->_bf._size);␊ |
140 | ␉fp->_flags &= ~__SMOD;␉/* buffer contents are again pristine */␊ |
141 | ␉if (fp->_r <= 0) {␊ |
142 | ␉␉if (fp->_r == 0)␊ |
143 | ␉␉␉fp->_flags |= __SEOF;␊ |
144 | ␉␉else {␊ |
145 | ␉␉␉fp->_r = 0;␊ |
146 | ␉␉␉fp->_flags |= __SERR;␊ |
147 | ␉␉}␊ |
148 | ␉␉return (EOF);␊ |
149 | ␉}␊ |
150 | ␉return (0);␊ |
151 | }␊ |
152 | ␊ |
153 | int␊ |
154 | __srefill(FILE *fp)␊ |
155 | {␊ |
156 | ␉int ret;␊ |
157 | ␊ |
158 | ␉if ((ret = __srefill0(fp)) <= 0)␊ |
159 | ␉␉return ret;␊ |
160 | ␉return __srefill1(fp);␊ |
161 | }␊ |
162 | |