xref: /xnu-8796.121.2/tests/dev_zero.c (revision c54f35ca767986246321eb901baf8f5ff7923f6a)
1*c54f35caSApple OSS Distributions #include <stdio.h>
2*c54f35caSApple OSS Distributions #include <fcntl.h>
3*c54f35caSApple OSS Distributions #include <util.h>
4*c54f35caSApple OSS Distributions #include <unistd.h>
5*c54f35caSApple OSS Distributions #include <darwintest.h>
6*c54f35caSApple OSS Distributions 
7*c54f35caSApple OSS Distributions T_DECL(dev_zero,
8*c54f35caSApple OSS Distributions     "test reading from /dev/zero",
9*c54f35caSApple OSS Distributions     T_META_ASROOT(false))
10*c54f35caSApple OSS Distributions {
11*c54f35caSApple OSS Distributions 	int dev = opendev("/dev/zero", O_RDONLY, NULL, NULL);
12*c54f35caSApple OSS Distributions 	char buffer[100];
13*c54f35caSApple OSS Distributions 
14*c54f35caSApple OSS Distributions 	for (int i = 0; i < 100; i++) {
15*c54f35caSApple OSS Distributions 		buffer[i] = 0xff;
16*c54f35caSApple OSS Distributions 	}
17*c54f35caSApple OSS Distributions 
18*c54f35caSApple OSS Distributions 	int rd_sz = read(dev, buffer, sizeof(buffer));
19*c54f35caSApple OSS Distributions 
20*c54f35caSApple OSS Distributions 	T_EXPECT_EQ(rd_sz, 100, "read from /dev/zero failed");
21*c54f35caSApple OSS Distributions 
22*c54f35caSApple OSS Distributions 	for (int i = 0; i < 100; i++) {
23*c54f35caSApple OSS Distributions 		if (buffer[i]) {
24*c54f35caSApple OSS Distributions 			T_FAIL("Unexpected non-zero character read from /dev/zero");
25*c54f35caSApple OSS Distributions 		}
26*c54f35caSApple OSS Distributions 	}
27*c54f35caSApple OSS Distributions 
28*c54f35caSApple OSS Distributions 	close(dev);
29*c54f35caSApple OSS Distributions }
30