xref: /xnu-11215.81.4/tests/dev_zero.c (revision d4514f0bc1d3f944c22d92e68b646ac3fb40d452)
1*d4514f0bSApple OSS Distributions #include <stdio.h>
2*d4514f0bSApple OSS Distributions #include <fcntl.h>
3*d4514f0bSApple OSS Distributions #include <util.h>
4*d4514f0bSApple OSS Distributions #include <unistd.h>
5*d4514f0bSApple OSS Distributions #include <darwintest.h>
6*d4514f0bSApple OSS Distributions 
7*d4514f0bSApple OSS Distributions T_DECL(dev_zero,
8*d4514f0bSApple OSS Distributions     "test reading from /dev/zero",
9*d4514f0bSApple OSS Distributions     T_META_ASROOT(false))
10*d4514f0bSApple OSS Distributions {
11*d4514f0bSApple OSS Distributions 	int dev = opendev("/dev/zero", O_RDONLY, 0, NULL);
12*d4514f0bSApple OSS Distributions 	char buffer[100];
13*d4514f0bSApple OSS Distributions 
14*d4514f0bSApple OSS Distributions 	for (int i = 0; i < 100; i++) {
15*d4514f0bSApple OSS Distributions 		buffer[i] = 0xff;
16*d4514f0bSApple OSS Distributions 	}
17*d4514f0bSApple OSS Distributions 
18*d4514f0bSApple OSS Distributions 	int rd_sz = read(dev, buffer, sizeof(buffer));
19*d4514f0bSApple OSS Distributions 
20*d4514f0bSApple OSS Distributions 	T_EXPECT_EQ(rd_sz, 100, "read from /dev/zero failed");
21*d4514f0bSApple OSS Distributions 
22*d4514f0bSApple OSS Distributions 	for (int i = 0; i < 100; i++) {
23*d4514f0bSApple OSS Distributions 		if (buffer[i]) {
24*d4514f0bSApple OSS Distributions 			T_FAIL("Unexpected non-zero character read from /dev/zero");
25*d4514f0bSApple OSS Distributions 		}
26*d4514f0bSApple OSS Distributions 	}
27*d4514f0bSApple OSS Distributions 
28*d4514f0bSApple OSS Distributions 	close(dev);
29*d4514f0bSApple OSS Distributions }
30