#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>

main()
{FILE *fp;
 pid_t IsParent;
 fp=fopen("fork.dat","r+");
 printf("!\n"); 
 IsParent=fork();
 if (IsParent) {
  fseek(fp,5,SEEK_SET);
  sleep(2);
 }
 else {
  sleep(1);
  fprintf(fp,"TEST"); 
 }
}