xref: /xnu-8796.141.3/tests/dev_zero.c (revision 1b191cb58250d0705d8a51287127505aa4bc0789)
1*1b191cb5SApple OSS Distributions #include <stdio.h>
2*1b191cb5SApple OSS Distributions #include <fcntl.h>
3*1b191cb5SApple OSS Distributions #include <util.h>
4*1b191cb5SApple OSS Distributions #include <unistd.h>
5*1b191cb5SApple OSS Distributions #include <darwintest.h>
6*1b191cb5SApple OSS Distributions 
7*1b191cb5SApple OSS Distributions T_DECL(dev_zero,
8*1b191cb5SApple OSS Distributions     "test reading from /dev/zero",
9*1b191cb5SApple OSS Distributions     T_META_ASROOT(false))
10*1b191cb5SApple OSS Distributions {
11*1b191cb5SApple OSS Distributions 	int dev = opendev("/dev/zero", O_RDONLY, NULL, NULL);
12*1b191cb5SApple OSS Distributions 	char buffer[100];
13*1b191cb5SApple OSS Distributions 
14*1b191cb5SApple OSS Distributions 	for (int i = 0; i < 100; i++) {
15*1b191cb5SApple OSS Distributions 		buffer[i] = 0xff;
16*1b191cb5SApple OSS Distributions 	}
17*1b191cb5SApple OSS Distributions 
18*1b191cb5SApple OSS Distributions 	int rd_sz = read(dev, buffer, sizeof(buffer));
19*1b191cb5SApple OSS Distributions 
20*1b191cb5SApple OSS Distributions 	T_EXPECT_EQ(rd_sz, 100, "read from /dev/zero failed");
21*1b191cb5SApple OSS Distributions 
22*1b191cb5SApple OSS Distributions 	for (int i = 0; i < 100; i++) {
23*1b191cb5SApple OSS Distributions 		if (buffer[i]) {
24*1b191cb5SApple OSS Distributions 			T_FAIL("Unexpected non-zero character read from /dev/zero");
25*1b191cb5SApple OSS Distributions 		}
26*1b191cb5SApple OSS Distributions 	}
27*1b191cb5SApple OSS Distributions 
28*1b191cb5SApple OSS Distributions 	close(dev);
29*1b191cb5SApple OSS Distributions }
30