selftests/efivarfs/create-read.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <stdio.h>
0003 #include <stdint.h>
0004 #include <stdlib.h>
0005 #include <unistd.h>
0006 #include <sys/types.h>
0007 #include <sys/stat.h>
0008 #include <fcntl.h>
0009 #include <errno.h>
0010 #include <string.h>
0011
0012 int main(int argc, char **argv)
0013 {
0014     const char *path;
0015     char buf[4];
0016     int fd, rc;
0017
0018     if (argc < 2) {
0019         fprintf(stderr, "usage: %s <path>\n", argv[0]);
0020         return EXIT_FAILURE;
0021     }
0022
0023     path = argv[1];
0024
0025     /* create a test variable */
0026     fd = open(path, O_RDWR | O_CREAT, 0600);
0027     if (fd < 0) {
0028         perror("open(O_WRONLY)");
0029         return EXIT_FAILURE;
0030     }
0031
0032     rc = read(fd, buf, sizeof(buf));
0033     if (rc != 0) {
0034         fprintf(stderr, "Reading a new var should return EOF\n");
0035         return EXIT_FAILURE;
0036     }
0037
0038     return EXIT_SUCCESS;
0039 }