xref: /xnu-8792.41.9/tests/dev_zero.c (revision 5c2921b07a2480ab43ec66f5b9e41cb872bc554f)
1*5c2921b0SApple OSS Distributions #include <stdio.h>
2*5c2921b0SApple OSS Distributions #include <fcntl.h>
3*5c2921b0SApple OSS Distributions #include <util.h>
4*5c2921b0SApple OSS Distributions #include <unistd.h>
5*5c2921b0SApple OSS Distributions #include <darwintest.h>
6*5c2921b0SApple OSS Distributions 
7*5c2921b0SApple OSS Distributions T_DECL(dev_zero,
8*5c2921b0SApple OSS Distributions     "test reading from /dev/zero",
9*5c2921b0SApple OSS Distributions     T_META_ASROOT(false))
10*5c2921b0SApple OSS Distributions {
11*5c2921b0SApple OSS Distributions 	int dev = opendev("/dev/zero", O_RDONLY, NULL, NULL);
12*5c2921b0SApple OSS Distributions 	char buffer[100];
13*5c2921b0SApple OSS Distributions 
14*5c2921b0SApple OSS Distributions 	for (int i = 0; i < 100; i++) {
15*5c2921b0SApple OSS Distributions 		buffer[i] = 0xff;
16*5c2921b0SApple OSS Distributions 	}
17*5c2921b0SApple OSS Distributions 
18*5c2921b0SApple OSS Distributions 	int rd_sz = read(dev, buffer, sizeof(buffer));
19*5c2921b0SApple OSS Distributions 
20*5c2921b0SApple OSS Distributions 	T_EXPECT_EQ(rd_sz, 100, "read from /dev/zero failed");
21*5c2921b0SApple OSS Distributions 
22*5c2921b0SApple OSS Distributions 	for (int i = 0; i < 100; i++) {
23*5c2921b0SApple OSS Distributions 		if (buffer[i]) {
24*5c2921b0SApple OSS Distributions 			T_FAIL("Unexpected non-zero character read from /dev/zero");
25*5c2921b0SApple OSS Distributions 		}
26*5c2921b0SApple OSS Distributions 	}
27*5c2921b0SApple OSS Distributions 
28*5c2921b0SApple OSS Distributions 	close(dev);
29*5c2921b0SApple OSS Distributions }
30