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 /* Open it in read-write mode. */
55 fp = fopen (TESTFILE, "r+");
58 if (fseek (fp, 3, SEEK_CUR))
60 if (fwrite ("g", 1, 1, fp) < 1)
64 if (fwrite ("bz", 1, 2, fp) < 2)
66 /* Discard pending write. */
67 ASSERT (fpurge (fp) == 0);
68 ASSERT (fclose (fp) == 0);
70 /* Open it in read-only mode. */
71 fp = fopen (TESTFILE, "r");
76 if (fread (buf, 1, 7, fp) < 7)
78 ASSERT (memcmp (buf, "foogars", 7) == 0);
80 /* Discard the buffered 'h', leaving position at EOF. */
81 ASSERT (fpurge (fp) == 0);
82 ASSERT (getc (fp) == EOF);
83 ASSERT (fclose (fp) == 0);
85 /* Ensure that purging a read does not corrupt subsequent writes. */
86 fp = fopen (TESTFILE, "r+");
88 ASSERT (fseek (fp, -1, SEEK_END) == 0);
89 ASSERT (getc (fp) == 'h');
90 ASSERT (getc (fp) == EOF);
91 ASSERT (fpurge (fp) == 0);
92 ASSERT (putc ('!', fp) == '!');
93 ASSERT (fclose (fp) == 0);
94 fp = fopen (TESTFILE, "r");
98 ASSERT (fread (buf, 1, 9, fp) == 9);
99 ASSERT (memcmp (buf, "foogarsh!", 9) == 0);
106 fprintf (stderr, "Skipping test: prerequisite file operations failed.\n");