#include <stdio.h>
#include <fcntl.h>

int main(int argc, char *argv[], char *envp[]) {
  int fd;
  char c;
  int i;
  int cnt;
  char buf[512];

  if (argc != 3) {
    printf("Usage: %s [input_file] [character]", argv[0]);
    return -1;
  }

  setuid(0);
  /* Do something that requires root */

  fd = open(argv[1], O_RDONLY);
  if (fd <= 0) {
    perror("open");
    return -1;
  }

  c = argv[2][0];

  read(fd, buf, 1024);

  for (i =0; i < 512; i++) {
    if (buf[i] == c) cnt++;
  }

  printf("Found %d occurrences of %c\n", cnt, c);

  return 0;
}