xref: /xnu-10002.61.3/tests/dev_zero.c (revision 0f4c859e951fba394238ab619495c4e1d54d0f34)
1*0f4c859eSApple OSS Distributions #include <stdio.h>
2*0f4c859eSApple OSS Distributions #include <fcntl.h>
3*0f4c859eSApple OSS Distributions #include <util.h>
4*0f4c859eSApple OSS Distributions #include <unistd.h>
5*0f4c859eSApple OSS Distributions #include <darwintest.h>
6*0f4c859eSApple OSS Distributions 
7*0f4c859eSApple OSS Distributions T_DECL(dev_zero,
8*0f4c859eSApple OSS Distributions     "test reading from /dev/zero",
9*0f4c859eSApple OSS Distributions     T_META_ASROOT(false))
10*0f4c859eSApple OSS Distributions {
11*0f4c859eSApple OSS Distributions 	int dev = opendev("/dev/zero", O_RDONLY, 0, NULL);
12*0f4c859eSApple OSS Distributions 	char buffer[100];
13*0f4c859eSApple OSS Distributions 
14*0f4c859eSApple OSS Distributions 	for (int i = 0; i < 100; i++) {
15*0f4c859eSApple OSS Distributions 		buffer[i] = 0xff;
16*0f4c859eSApple OSS Distributions 	}
17*0f4c859eSApple OSS Distributions 
18*0f4c859eSApple OSS Distributions 	int rd_sz = read(dev, buffer, sizeof(buffer));
19*0f4c859eSApple OSS Distributions 
20*0f4c859eSApple OSS Distributions 	T_EXPECT_EQ(rd_sz, 100, "read from /dev/zero failed");
21*0f4c859eSApple OSS Distributions 
22*0f4c859eSApple OSS Distributions 	for (int i = 0; i < 100; i++) {
23*0f4c859eSApple OSS Distributions 		if (buffer[i]) {
24*0f4c859eSApple OSS Distributions 			T_FAIL("Unexpected non-zero character read from /dev/zero");
25*0f4c859eSApple OSS Distributions 		}
26*0f4c859eSApple OSS Distributions 	}
27*0f4c859eSApple OSS Distributions 
28*0f4c859eSApple OSS Distributions 	close(dev);
29*0f4c859eSApple OSS Distributions }
30