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 for (check_filepos = 0; check_filepos <= 1; check_filepos++)
49 /* Create a file with some contents. */
50 fp = fopen (TESTFILE, "w");
53 if (fwrite ("foobarsh", 1, 8, fp) < 8)
58 /* The file's contents is now "foobarsh". */
60 /* Open it in read-write mode. */
61 fp = fopen (TESTFILE, "r+");
64 if (fseek (fp, 3, SEEK_CUR))
66 if (fwrite ("g", 1, 1, fp) < 1)
70 if (fwrite ("bz", 1, 2, fp) < 2)
72 /* Discard pending write. */
73 ASSERT (fpurge (fp) == 0);
74 /* Verify that when discarding pending output, the file position is set
75 back to where it was before the write calls. */
77 ASSERT (ftell (fp) == 4);
78 ASSERT (fclose (fp) == 0);
80 /* Open it in read-only mode. */
81 fp = fopen (TESTFILE, "r");
84 /* Verify that the pending writes before the fpurge were really
88 if (fread (buf, 1, 7, fp) < 7)
90 ASSERT (memcmp (buf, "foogars", 7) == 0);
92 /* Discard the buffered 'h'. */
94 ASSERT (ftell (fp) == 7);
95 ASSERT (fpurge (fp) == 0);
96 /* Verify that when discarding pending input, the file position is
97 advanced to match the end of the previously read input. */
99 ASSERT (ftell (fp) == 8);
100 ASSERT (getc (fp) == EOF);
101 ASSERT (fclose (fp) == 0);
103 /* The file's contents is now "foogarsh". */
105 /* Ensure that purging a read does not corrupt subsequent writes. */
106 fp = fopen (TESTFILE, "r+");
109 if (fseek (fp, -1, SEEK_END))
111 ASSERT (getc (fp) == 'h');
112 ASSERT (getc (fp) == EOF);
114 ASSERT (ftell (fp) == 8);
115 ASSERT (fpurge (fp) == 0);
117 ASSERT (ftell (fp) == 8);
118 ASSERT (putc ('!', fp) == '!');
119 ASSERT (fclose (fp) == 0);
120 fp = fopen (TESTFILE, "r");
125 ASSERT (fread (buf, 1, 10, fp) == 9);
126 ASSERT (memcmp (buf, "foogarsh!", 9) == 0);
128 ASSERT (fclose (fp) == 0);
130 /* The file's contents is now "foogarsh!". */
137 fprintf (stderr, "Skipping test: prerequisite file operations failed.\n");