LXR linux/tools/testing/selftests/efivarfs/create-read.c

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