preadv.c revision 1.4 
1/*	$OpenBSD: preadv.c,v 1.4 2011/11/06 15:00:34 guenther Exp $	*/
2/*
3 *	Written by Artur Grabowski <art@openbsd.org> 2002 Public Domain.
4 */
5#include <sys/types.h>
6#include <sys/uio.h>
7#include <err.h>
8#include <errno.h>
9#include <fcntl.h>
10#include <limits.h>
11#include <stdio.h>
12#include <stdlib.h>
13#include <unistd.h>
14
15int
16main(int argc, char *argv[])
17{
18	char temp[] = "/tmp/dup2XXXXXXXXX";
19	const char magic[10] = "0123456789";
20	char c, c1, c2;
21	int fd, ret;
22	struct iovec iv[2];
23
24	if ((fd = mkstemp(temp)) < 0)
25		err(1, "mkstemp");
26	remove(temp);
27
28	if (write(fd, magic, sizeof(magic)) != sizeof(magic))
29		err(1, "write");
30
31	if (lseek(fd, 0, SEEK_SET) != 0)
32		err(1, "lseek");
33
34	if (read(fd, &c, 1) != 1)
35		err(1, "read1");
36
37	if (c != magic[0])
38		errx(1, "read1 %c != %c", c, magic[0]);
39
40	iv[0].iov_base = &c1;
41	iv[0].iov_len = 1;
42	iv[1].iov_base = &c2;
43	iv[1].iov_len = 1;
44
45	if (preadv(fd, iv, 2, 7) != 2)
46		err(1, "preadv");
47
48	if (c1 != magic[7])
49		errx(1, "preadv %c != %c", c1, magic[7]);
50
51	if (c2 != magic[8])
52		errx(1, "preadv %c != %c", c2, magic[7]);
53
54	if (read(fd, &c, 1) != 1)
55		err(1, "read2");
56
57	if (c != magic[1])
58		errx(1, "read2 %c != %c", c, magic[1]);
59
60	if ((ret = preadv(fd, iv, 2, -1)) != -1)
61		errx(1, "preadv with negative offset succeeded,\
62				returning %d", ret);
63	if (errno != EINVAL)
64		err(1, "pread with negative offset");
65
66	if ((ret = preadv(fd, iv, 2, LLONG_MAX)) != -1)
67		errx(1, "preadv with wrapping offset succeeded,\
68				returning %d", ret);
69	if (errno != EINVAL)
70		err(1, "pread with wrapping offset");
71
72	if (read(fd, &c, 1) != 1)
73		err(1, "read3");
74
75	if (c != magic[2])
76		errx(1, "read3 %c != %c", c, magic[2]);
77
78	close(fd);
79
80	/* also, verify that preadv fails on ttys */
81	fd = open("/dev/tty", O_RDWR);
82	if (fd < 0)
83		printf("skipping tty test\n");
84	else if ((ret = preadv(fd, iv, 2, 7)) != -1)
85		errx(1, "preadv succeeded on tty, returning %d", ret);
86	else if (errno != ESPIPE)
87		err(1, "preadv");
88
89	return 0;
90}
91