1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
/* Test of fwriting() function.
Copyright (C) 2007 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Written by Bruno Haible <bruno@clisp.org>, 2007. */
#include <config.h>
#include "fwriting.h"
#include <stdio.h>
#include <stdlib.h>
#define ASSERT(expr) \
do \
{ \
if (!(expr)) \
{ \
fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
abort (); \
} \
} \
while (0)
#define TESTFILE "t-fwriting.tmp"
int
main ()
{
FILE *fp;
/* Create a file with some contents. Write-only file is always writing. */
fp = fopen (TESTFILE, "w");
if (fp == NULL)
goto skip;
ASSERT (fwriting (fp));
if (fwrite ("foobarsh", 1, 8, fp) < 8)
goto skip;
ASSERT (fwriting (fp));
if (fclose (fp))
goto skip;
/* Open it in read-only mode. Read-only file is never writing. */
fp = fopen (TESTFILE, "r");
if (fp == NULL)
goto skip;
ASSERT (!fwriting (fp));
if (fgetc (fp) != 'f')
goto skip;
ASSERT (!fwriting (fp));
if (fseek (fp, 2, SEEK_CUR))
goto skip;
ASSERT (!fwriting (fp));
if (fgetc (fp) != 'b')
goto skip;
ASSERT (!fwriting (fp));
fflush (fp);
ASSERT (!fwriting (fp));
if (fgetc (fp) != 'a')
goto skip;
ASSERT (!fwriting (fp));
if (fseek (fp, 0, SEEK_END))
goto skip;
ASSERT (!fwriting (fp));
if (fclose (fp))
goto skip;
/* Open it in read-write mode. POSIX requires a reposition (fseek,
fsetpos, rewind) or fflush when transitioning from write to read,
fwriting is only deterministic after input or output, but this
test case should be portable even on open, after reposition, and
after fflush. */
/* First a scenario with only fgetc, fseek, fputc. */
fp = fopen (TESTFILE, "r+");
if (fp == NULL)
goto skip;
ASSERT (!fwriting (fp));
if (fgetc (fp) != 'f')
goto skip;
ASSERT (!fwriting (fp));
if (fseek (fp, 2, SEEK_CUR))
goto skip;
ASSERT (!fwriting (fp));
if (fgetc (fp) != 'b')
goto skip;
ASSERT (!fwriting (fp));
/* This fseek call is necessary when switching from reading to writing.
See the description of fopen(), ISO C 99 7.19.5.3.(6). */
if (fseek (fp, 0, SEEK_CUR) != 0)
goto skip;
ASSERT (!fwriting (fp));
if (fputc ('x', fp) != 'x')
goto skip;
ASSERT (fwriting (fp));
if (fseek (fp, 0, SEEK_END))
goto skip;
/* freading (fp) is undefined here, because on some implementations (e.g.
glibc) fseek causes a buffer to be read.
fwriting (fp) is undefined as well. */
if (fclose (fp))
goto skip;
/* Open it in read-write mode. POSIX requires a reposition (fseek,
fsetpos, rewind) or fflush when transitioning from write to read,
fwriting is only deterministic after input or output, but this
test case should be portable even on open, after reposition, and
after fflush. */
/* Here a scenario that includes fflush. */
fp = fopen (TESTFILE, "r+");
if (fp == NULL)
goto skip;
ASSERT (!fwriting (fp));
if (fgetc (fp) != 'f')
goto skip;
ASSERT (!fwriting (fp));
if (fseek (fp, 2, SEEK_CUR))
goto skip;
ASSERT (!fwriting (fp));
if (fgetc (fp) != 'b')
goto skip;
ASSERT (!fwriting (fp));
fflush (fp);
ASSERT (!fwriting (fp));
if (fgetc (fp) != 'x')
goto skip;
ASSERT (!fwriting (fp));
/* This fseek call is necessary when switching from reading to writing.
See the description of fopen(), ISO C 99 7.19.5.3.(6). */
if (fseek (fp, 0, SEEK_CUR) != 0)
goto skip;
ASSERT (!fwriting (fp));
if (fputc ('z', fp) != 'z')
goto skip;
ASSERT (fwriting (fp));
if (fseek (fp, 0, SEEK_END))
goto skip;
/* freading (fp) is undefined here, because on some implementations (e.g.
glibc) fseek causes a buffer to be read.
fwriting (fp) is undefined as well. */
if (fclose (fp))
goto skip;
/* Open it in append mode. */
fp = fopen (TESTFILE, "a");
if (fp == NULL)
goto skip;
ASSERT (fwriting (fp));
if (fwrite ("bla", 1, 3, fp) < 3)
goto skip;
ASSERT (fwriting (fp));
if (fclose (fp))
goto skip;
return 0;
skip:
fprintf (stderr, "Skipping test: file operations failed.\n");
return 77;
}
|
