xref: /xnu-8020.140.41/tests/dev_zero.c (revision 27b03b360a988dfd3dfdf34262bb0042026747cc)
1*27b03b36SApple OSS Distributions #include <stdio.h>
2*27b03b36SApple OSS Distributions #include <fcntl.h>
3*27b03b36SApple OSS Distributions #include <util.h>
4*27b03b36SApple OSS Distributions #include <unistd.h>
5*27b03b36SApple OSS Distributions #include <darwintest.h>
6*27b03b36SApple OSS Distributions 
7*27b03b36SApple OSS Distributions T_DECL(dev_zero,
8*27b03b36SApple OSS Distributions     "test reading from /dev/zero",
9*27b03b36SApple OSS Distributions     T_META_ASROOT(false))
10*27b03b36SApple OSS Distributions {
11*27b03b36SApple OSS Distributions 	int dev = opendev("/dev/zero", O_RDONLY, NULL, NULL);
12*27b03b36SApple OSS Distributions 	char buffer[100];
13*27b03b36SApple OSS Distributions 
14*27b03b36SApple OSS Distributions 	for (int i = 0; i < 100; i++) {
15*27b03b36SApple OSS Distributions 		buffer[i] = 0xff;
16*27b03b36SApple OSS Distributions 	}
17*27b03b36SApple OSS Distributions 
18*27b03b36SApple OSS Distributions 	int rd_sz = read(dev, buffer, sizeof(buffer));
19*27b03b36SApple OSS Distributions 
20*27b03b36SApple OSS Distributions 	T_EXPECT_EQ(rd_sz, 100, "read from /dev/zero failed");
21*27b03b36SApple OSS Distributions 
22*27b03b36SApple OSS Distributions 	for (int i = 0; i < 100; i++) {
23*27b03b36SApple OSS Distributions 		if (buffer[i]) {
24*27b03b36SApple OSS Distributions 			T_FAIL("Unexpected non-zero character read from /dev/zero");
25*27b03b36SApple OSS Distributions 		}
26*27b03b36SApple OSS Distributions 	}
27*27b03b36SApple OSS Distributions 
28*27b03b36SApple OSS Distributions 	close(dev);
29*27b03b36SApple OSS Distributions }
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