xref: /linux/tools/testing/selftests/efivarfs/create-read.c (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <stdio.h>
3 #include <stdint.h>
4 #include <stdlib.h>
5 #include <unistd.h>
6 #include <sys/types.h>
7 #include <sys/stat.h>
8 #include <fcntl.h>
9 #include <errno.h>
10 #include <string.h>
11 
main(int argc,char ** argv)12 int main(int argc, char **argv)
13 {
14 	const char *path;
15 	char buf[4];
16 	int fd, rc;
17 
18 	if (argc < 2) {
19 		fprintf(stderr, "usage: %s <path>\n", argv[0]);
20 		return EXIT_FAILURE;
21 	}
22 
23 	path = argv[1];
24 
25 	/* create a test variable */
26 	fd = open(path, O_RDWR | O_CREAT, 0600);
27 	if (fd < 0) {
28 		perror("open(O_WRONLY)");
29 		return EXIT_FAILURE;
30 	}
31 
32 	rc = read(fd, buf, sizeof(buf));
33 	if (rc != 0) {
34 		fprintf(stderr, "Reading a new var should return EOF\n");
35 		close(fd);
36 		return EXIT_FAILURE;
37 	}
38 
39 	close(fd);
40 	return EXIT_SUCCESS;
41 }
42