read04.c revision aabb8340f63ed31afe995fd97795e542dc68b93c 
1/*
2 *
3 *   Copyright (c) International Business Machines  Corp., 2001
4 *
5 *   This program is free software;  you can redistribute it and/or modify
6 *   it under the terms of the GNU General Public License as published by
7 *   the Free Software Foundation; either version 2 of the License, or
8 *   (at your option) any later version.
9 *
10 *   This program is distributed in the hope that it will be useful,
11 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13 *   the GNU General Public License for more details.
14 *
15 *   You should have received a copy of the GNU General Public License
16 *   along with this program;  if not, write to the Free Software
17 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20/*
21 * NAME
22 *	read04.c
23 *
24 * DESCRIPTION
25 *	Testcase to check if read returns the number of bytes read correctly.
26 *
27 * ALGORITHM
28 *	Create a file and write some bytes out to it.
29 *	Attempt to read more than written.
30 *	Check the return count, and the read buffer. The read buffer should be
31 *	same as the write buffer.
32 *
33 * USAGE:  <for command-line>
34 *  read04 [-c n] [-f] [-i n] [-I x] [-P x] [-t]
35 *     where,  -c n : Run n copies concurrently.
36 *             -f   : Turn off functionality Testing.
37 *             -i n : Execute test n times.
38 *             -I x : Execute test for x seconds.
39 *             -P x : Pause for x seconds between iterations.
40 *             -t   : Turn on syscall timing.
41 *
42 * HISTORY
43 *	07/2001 Ported by Wayne Boyer
44 *
45 * RESTRICTIONS
46 *	None
47 */
48#include <sys/types.h>
49#include <sys/stat.h>
50#include <stdio.h>
51#include <fcntl.h>
52#include <errno.h>
53#include "test.h"
54
55void cleanup(void);
56void setup(void);
57
58char *TCID = "read04";
59int TST_TOTAL = 1;
60
61#define TST_SIZE	27	/* could also do strlen(palfa) */
62char fname[255];
63char palfa[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
64int fild;
65
66int main(int ac, char **av)
67{
68	int lc;
69	const char *msg;
70
71	int rfild;
72	char prbuf[BUFSIZ];
73
74	/*
75	 * parse standard options
76	 */
77	if ((msg = parse_opts(ac, av, NULL, NULL)) != NULL) {
78		tst_brkm(TBROK, NULL, "OPTION PARSING ERROR - %s", msg);
79	}
80
81	setup();		/* global setup for test */
82
83	for (lc = 0; TEST_LOOPING(lc); lc++) {
84
85		tst_count = 0;	/* reset tst_count while looping */
86
87		if ((rfild = open(fname, O_RDONLY)) == -1) {
88			tst_brkm(TBROK, cleanup, "can't open for reading");
89		}
90		TEST(read(rfild, prbuf, BUFSIZ));
91
92		if (TEST_RETURN == -1) {
93			tst_resm(TFAIL, "call failed unexpectedly");
94			continue;
95		}
96
97		if (TEST_RETURN != TST_SIZE) {
98			tst_resm(TFAIL, "Bad read count - got %ld - "
99				 "expected %d", TEST_RETURN, TST_SIZE);
100			continue;
101		}
102		if (memcmp(palfa, prbuf, TST_SIZE) != 0) {
103			tst_resm(TFAIL, "read buffer not equal "
104				 "to write buffer");
105			continue;
106		}
107		tst_resm(TPASS, "functionality of read() is correct");
108
109		if (close(rfild) == -1) {
110			tst_brkm(TBROK, cleanup, "close() failed");
111		}
112	}
113
114	cleanup();
115	tst_exit();
116}
117
118/*
119 * setup() - performs all ONE TIME setup for this test
120 */
121void setup(void)
122{
123
124	tst_sig(NOFORK, DEF_HANDLER, cleanup);
125
126	umask(0);
127
128	TEST_PAUSE;
129
130	tst_tmpdir();
131
132	sprintf(fname, "tfile_%d", getpid());
133
134	if ((fild = creat(fname, 0777)) == -1) {
135		tst_brkm(TBROK, cleanup, "creat(%s, 0777) Failed, errno = %d"
136			 " : %s", fname, errno, strerror(errno));
137	}
138	if (write(fild, palfa, TST_SIZE) != TST_SIZE) {
139		tst_brkm(TBROK, cleanup, "can't write to Xread");
140	}
141	close(fild);
142}
143
144/*
145 * cleanup() - performs all ONE TIME cleanup for this test at completion or
146 *	       premature exit.
147 */
148void cleanup(void)
149{
150
151	unlink(fname);
152	tst_rmdir();
153
154}
155