xref: /xnu-10063.141.1/tests/dev_zero.c (revision d8b80295118ef25ac3a784134bcf95cd8e88109f)
1*d8b80295SApple OSS Distributions #include <stdio.h>
2*d8b80295SApple OSS Distributions #include <fcntl.h>
3*d8b80295SApple OSS Distributions #include <util.h>
4*d8b80295SApple OSS Distributions #include <unistd.h>
5*d8b80295SApple OSS Distributions #include <darwintest.h>
6*d8b80295SApple OSS Distributions 
7*d8b80295SApple OSS Distributions T_DECL(dev_zero,
8*d8b80295SApple OSS Distributions     "test reading from /dev/zero",
9*d8b80295SApple OSS Distributions     T_META_ASROOT(false))
10*d8b80295SApple OSS Distributions {
11*d8b80295SApple OSS Distributions 	int dev = opendev("/dev/zero", O_RDONLY, 0, NULL);
12*d8b80295SApple OSS Distributions 	char buffer[100];
13*d8b80295SApple OSS Distributions 
14*d8b80295SApple OSS Distributions 	for (int i = 0; i < 100; i++) {
15*d8b80295SApple OSS Distributions 		buffer[i] = 0xff;
16*d8b80295SApple OSS Distributions 	}
17*d8b80295SApple OSS Distributions 
18*d8b80295SApple OSS Distributions 	int rd_sz = read(dev, buffer, sizeof(buffer));
19*d8b80295SApple OSS Distributions 
20*d8b80295SApple OSS Distributions 	T_EXPECT_EQ(rd_sz, 100, "read from /dev/zero failed");
21*d8b80295SApple OSS Distributions 
22*d8b80295SApple OSS Distributions 	for (int i = 0; i < 100; i++) {
23*d8b80295SApple OSS Distributions 		if (buffer[i]) {
24*d8b80295SApple OSS Distributions 			T_FAIL("Unexpected non-zero character read from /dev/zero");
25*d8b80295SApple OSS Distributions 		}
26*d8b80295SApple OSS Distributions 	}
27*d8b80295SApple OSS Distributions 
28*d8b80295SApple OSS Distributions 	close(dev);
29*d8b80295SApple OSS Distributions }
30