1 /* Test of fpurge() function.
2 Copyright (C) 2007-2009 Free Software Foundation, Inc.
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.
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.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* Written by Bruno Haible <bruno@clisp.org>, 2007. */
26 #define ASSERT(expr) \
31 fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
38 #define TESTFILE "t-fpurge.tmp"
45 /* Create a file with some contents. */
46 fp = fopen (TESTFILE, "w");
49 if (fwrite ("foobarsh", 1, 8, fp) < 8)
54 /* The file's contents is now "foobarsh". */
56 /* Open it in read-write mode. */
57 fp = fopen (TESTFILE, "r+");
60 if (fseek (fp, 3, SEEK_CUR))
62 if (fwrite ("g", 1, 1, fp) < 1)
66 if (fwrite ("bz", 1, 2, fp) < 2)
68 /* Discard pending write. */
69 ASSERT (fpurge (fp) == 0);
70 ASSERT (fclose (fp) == 0);
72 /* Open it in read-only mode. */
73 fp = fopen (TESTFILE, "r");
78 if (fread (buf, 1, 7, fp) < 7)
80 ASSERT (memcmp (buf, "foogars", 7) == 0);
82 /* Discard the buffered 'h', leaving position at EOF. */
83 ASSERT (fpurge (fp) == 0);
84 ASSERT (getc (fp) == EOF);
85 ASSERT (fclose (fp) == 0);
87 /* The file's contents is now "foogarsh". */
89 /* Ensure that purging a read does not corrupt subsequent writes. */
90 fp = fopen (TESTFILE, "r+");
93 if (fseek (fp, -1, SEEK_END))
95 ASSERT (getc (fp) == 'h');
96 ASSERT (getc (fp) == EOF);
97 ASSERT (fpurge (fp) == 0);
98 ASSERT (putc ('!', fp) == '!');
99 ASSERT (fclose (fp) == 0);
100 fp = fopen (TESTFILE, "r");
105 ASSERT (fread (buf, 1, 10, fp) == 9);
106 ASSERT (memcmp (buf, "foogarsh!", 9) == 0);
108 ASSERT (fclose (fp) == 0);
110 /* The file's contents is now "foogarsh!". */
116 fprintf (stderr, "Skipping test: prerequisite file operations failed.\n");