char inFile[1024]="input.txt";
char outFile[1024]="output.txt";
int main(int argc, char **argv)
{
  pid_t pid=1;
  int no=0;           // no. of command
  char command[1024]; // contain each line of input file
  ...........
 while (pid && fgets(command,1023,iFile)!=NULL)
{
        if (pid==0){
    
      //TODO: Child process
      //      Run command and write output to file
      //      Child process should sleep 1 second to wait parent prcess
      //        to finish writing to output file
 
    else if (pid>0)
  {
 
      //TODO: Parent process
      //      Write the no. of command to file
      //      Wait child process to finish
 
    }