xref: /xnu-11215/tests/dev_zero.c (revision 1031c584)
1e6231be0SApple OSS Distributions #include <stdio.h>
2e6231be0SApple OSS Distributions #include <fcntl.h>
3e6231be0SApple OSS Distributions #include <util.h>
4e6231be0SApple OSS Distributions #include <unistd.h>
5e6231be0SApple OSS Distributions #include <darwintest.h>
6e6231be0SApple OSS Distributions 
7e6231be0SApple OSS Distributions T_DECL(dev_zero,
8e6231be0SApple OSS Distributions     "test reading from /dev/zero",
9e6231be0SApple OSS Distributions     T_META_ASROOT(false))
10e6231be0SApple OSS Distributions {
11*1031c584SApple OSS Distributions 	int dev = opendev("/dev/zero", O_RDONLY, 0, NULL);
12e6231be0SApple OSS Distributions 	char buffer[100];
13e6231be0SApple OSS Distributions 
14e6231be0SApple OSS Distributions 	for (int i = 0; i < 100; i++) {
15e6231be0SApple OSS Distributions 		buffer[i] = 0xff;
16e6231be0SApple OSS Distributions 	}
17e6231be0SApple OSS Distributions 
18e6231be0SApple OSS Distributions 	int rd_sz = read(dev, buffer, sizeof(buffer));
19e6231be0SApple OSS Distributions 
20e6231be0SApple OSS Distributions 	T_EXPECT_EQ(rd_sz, 100, "read from /dev/zero failed");
21e6231be0SApple OSS Distributions 
22e6231be0SApple OSS Distributions 	for (int i = 0; i < 100; i++) {
23e6231be0SApple OSS Distributions 		if (buffer[i]) {
24e6231be0SApple OSS Distributions 			T_FAIL("Unexpected non-zero character read from /dev/zero");
25e6231be0SApple OSS Distributions 		}
26e6231be0SApple OSS Distributions 	}
27e6231be0SApple OSS Distributions 
28e6231be0SApple OSS Distributions 	close(dev);
29e6231be0SApple OSS Distributions }
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