gistfile1.c

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

int main()
{
  char c;
  pid_t pid;
  char* filename = "foofile";

  int fd = open(filename, O_RDWR);
  if (fd == -1) {
    /* Handle error */
  }
  read(fd, &c, 1);
  printf("root process:%c\n",c);

  pid = fork();
  if (pid == -1) {
    /* Handle error */
  }

  if (pid == 0) { /*child*/
    pread(fd, &c, 1, 1);
    printf("child:%c\n",c);
  }
  else { /*parent*/
    pread(fd, &c, 1, 1);
    printf("parent:%c\n",c);
  }
}