source: trunk/src/sed/gnulib-tests/test-freading.c@ 3635

Last change on this file since 3635 was 3611, checked in by bird, 14 months ago

vendor/sed/current: GNU sed 4.9 (sed-4.9.tar.xz sha256:6e226b732e1cd739464ad6862bd1a1aba42d7982922da7a53519631d24975181)
File size: 4.6 KB
Line 
1/* Test of freading() function.
2 Copyright (C) 2007-2022 Free Software Foundation, Inc.
3
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <https://www.gnu.org/licenses/>. */
16
17/* Written by Bruno Haible <bruno@clisp.org>, 2007. */
18
19#include <config.h>
20
21/* None of the files accessed by this test are large, so disable the
22 fseek link warning if we are not using the gnulib fseek module. */
23#define _GL_NO_LARGE_FILES
24#include "freading.h"
25
26#include <stdio.h>
27
28#include "macros.h"
29
30#define TESTFILE "t-freading.tmp"
31
32int
33main (void)
34{
35 FILE *fp;
36
37 /* Create a file with some contents. Write-only file is never reading. */
38 fp = fopen (TESTFILE, "w");
39 ASSERT (fp);
40 ASSERT (!freading (fp));
41 ASSERT (fwrite ("foobarsh", 1, 8, fp) == 8);
42 ASSERT (!freading (fp));
43 ASSERT (fclose (fp) == 0);
44
45 /* Open it in read-only mode. Read-only file is always reading. */
46 fp = fopen (TESTFILE, "r");
47 ASSERT (fp);
48 ASSERT (freading (fp));
49 ASSERT (fgetc (fp) == 'f');
50 ASSERT (freading (fp));
51 ASSERT (fseek (fp, 2, SEEK_CUR) == 0);
52 ASSERT (freading (fp));
53 ASSERT (fgetc (fp) == 'b');
54 ASSERT (freading (fp));
55 fflush (fp);
56 ASSERT (freading (fp));
57 ASSERT (fgetc (fp) == 'a');
58 ASSERT (freading (fp));
59 ASSERT (fseek (fp, 0, SEEK_END) == 0);
60 ASSERT (freading (fp));
61 ASSERT (fclose (fp) == 0);
62
63 /* Open it in read-write mode. POSIX requires a reposition (fseek,
64 fsetpos, rewind) or EOF when transitioning from read to write;
65 freading is only deterministic after input or output, but this
66 test case should be portable even on open, after reposition, and
67 at EOF. */
68 /* First a scenario with only fgetc, fseek, fputc. */
69 fp = fopen (TESTFILE, "r+");
70 ASSERT (fp);
71 ASSERT (!freading (fp));
72 ASSERT (fgetc (fp) == 'f');
73 ASSERT (freading (fp));
74 ASSERT (fseek (fp, 2, SEEK_CUR) == 0);
75 /* freading (fp) is undefined here, but fwriting (fp) is false. */
76 ASSERT (fgetc (fp) == 'b');
77 ASSERT (freading (fp));
78 /* This fseek call is necessary when switching from reading to writing.
79 See the description of fopen(), ISO C 99 7.19.5.3.(6). */
80 ASSERT (fseek (fp, 0, SEEK_CUR) == 0);
81 /* freading (fp) is undefined here, but fwriting (fp) is false. */
82 ASSERT (fputc ('x', fp) == 'x');
83 ASSERT (!freading (fp));
84 ASSERT (fseek (fp, 0, SEEK_END) == 0);
85 /* freading (fp) is undefined here, because on some implementations (e.g.
86 glibc) fseek causes a buffer to be read.
87 fwriting (fp) is undefined as well. */
88 ASSERT (fclose (fp) == 0);
89
90 /* Open it in read-write mode. POSIX requires a reposition (fseek,
91 fsetpos, rewind) or EOF when transitioning from read to write;
92 freading is only deterministic after input or output, but this
93 test case should be portable even on open, after reposition, and
94 at EOF. */
95 /* Here a scenario that includes fflush. */
96 fp = fopen (TESTFILE, "r+");
97 ASSERT (fp);
98 ASSERT (!freading (fp));
99 ASSERT (fgetc (fp) == 'f');
100 ASSERT (freading (fp));
101 ASSERT (fseek (fp, 2, SEEK_CUR) == 0);
102 /* freading (fp) is undefined here, but fwriting (fp) is false. */
103 ASSERT (fgetc (fp) == 'b');
104 ASSERT (freading (fp));
105 fflush (fp);
106 /* freading (fp) is undefined here, but fwriting (fp) is false. */
107 ASSERT (fgetc (fp) == 'x');
108 ASSERT (freading (fp));
109 /* This fseek call is necessary when switching from reading to writing.
110 See the description of fopen(), ISO C 99 7.19.5.3.(6). */
111 ASSERT (fseek (fp, 0, SEEK_CUR) == 0);
112 /* freading (fp) is undefined here, but fwriting (fp) is false. */
113 ASSERT (fputc ('z', fp) == 'z');
114 ASSERT (!freading (fp));
115 ASSERT (fseek (fp, 0, SEEK_END) == 0);
116 /* freading (fp) is undefined here, because on some implementations (e.g.
117 glibc) fseek causes a buffer to be read.
118 fwriting (fp) is undefined as well. */
119 ASSERT (fclose (fp) == 0);
120
121 /* Open it in append mode. Write-only file is never reading. */
122 fp = fopen (TESTFILE, "a");
123 ASSERT (fp);
124 ASSERT (!freading (fp));
125 ASSERT (fwrite ("bla", 1, 3, fp) == 3);
126 ASSERT (!freading (fp));
127 ASSERT (fclose (fp) == 0);
128 ASSERT (remove (TESTFILE) == 0);
129 return 0;
130}
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