Design a program using ordinary pipes in which one process (e., parent process) sends the student's response to the exam difficulty-rating question...

Design a program using ordinary pipes in which one process (e.g., parent process) sends the student's response to the exam difficulty-rating question to a second process (e.g., child process). The second process sends a new message with the student's rating back to the first process. For example, the first process asks the student how s/he rates the difficulty of the exam 1. Then, the first process sends the student's response to the second process. If the student responds that the exam is ok, the second process sends back the following message to the first process: ">> Exam 1 is just right".

This will require two pipes:

- One pipe for sending the student's response from the first process to the second process.

- The other pipe for sending the new message from the second process to the first process.

Below is the output of the program:

How would you rate the difficulty of Exam 1? Enter E for Easy, O for ok, H for Hard: O answer: O

easy or hard: just right

child read... >just right<

child is writing...:Exam 1 is just right >> Exam 1 is just right! 

here is my code. I DON'T KNOW WHY IT DOESN'T PRINT OUT EXAM1

//

// exam_eval.c

// Assignment3_OrdinaryPipes

//

#include <stdio.h>

#include <unistd.h>

#include <sys/types.h>

#include <string.h>

#define BUFFER_SIZE 100

#define READ_END  0

#define WRITE_END  1

// Function prototypes

char isExamHard(void);

void request_rating(int firstPipe[], int secondPipe[]);

void respond_to_the_rating(int firstPipe[], int secondPipe[]);

int main(int argc, const char * argv[]) {

  int fd1[2];

  int fd2[2];

  // TODO: Create two pipes

  //    Terminate the program if fail to create the pipes

  if (pipe(fd1) == -1 || pipe(fd2) == -1) {

    fprintf(stderr, "Pipe failed.n");

    return 1;

  }

  pid_t pid = fork();

  // TODO: Create a child process

  //    Terminate the program if fail to fork a child process

  // TODO: parent process invokes request_rating

  //    child process invokes respond_to_the_rating

  if(pid == 0)

  {

    respond_to_the_rating(fd1,fd2);

  }else if(pid >0)

  {

    request_rating(fd1,fd2);

    wait(NULL);

    // close (fd1[READ_END]);

    // close (fd1[WRITE_END]);

    // close (fd2[WRITE_END]);

//    char read_msg[BUFFER_SIZE];

//    read(fd2[READ_END], read_msg, BUFFER_SIZE);

//    printf(">>Exam1 is %sn",read_msg);

//    close (fd2[READ_END]);

  }else{

    perror("Could not fork the process");

    exit(-1);

  }

  return 0;

}

/*********************************************************

 *            isExamHard           *

 * This function asks a question about Exam 1 difficulty *

 ********************************************************/

char isExamHard(void)

{

  char input;

  printf("How would you rate the difficulty of Exam 1?n");

  printf("Enter E for Easy, O for ok, H for Hard: ");

  scanf("%c", &input);

  return input;

}

/******************************************************

 *          request_rating         *

 * Asks the student to rate the exam #1, sends the  *

 * student's reponse to the second process and reads *

 * the message from the child process.        *

 *****************************************************/

void request_rating(int *first_pipe, int *second_pipe) {

  char level;

  char write_msg[BUFFER_SIZE];

  char read_msg[BUFFER_SIZE];

  level = isExamHard();

  printf("answer: %cn", level);

  if ((level == 'E') || (level == 'e')) {

    strcpy(write_msg, "easy");

  }

  else if ((level == 'O') || (level == 'o')) {

    strcpy(write_msg, "just right");

  }

  else {

    strcpy(write_msg, "hard");

  }

  printf("easy or hard: %sn", write_msg);

  //printf("Parent is requesting...n");

  close (first_pipe[READ_END]);

  close (second_pipe[WRITE_END]);

  //close (second_pipe[READ_END]);

  // TODO: write the student's response to the first pipe

  write(first_pipe[WRITE_END], write_msg,

     strlen(write_msg)+1);

  printf("Parent Wrote: %s n", write_msg);

  close (first_pipe[WRITE_END]);

  read(second_pipe[READ_END], read_msg, BUFFER_SIZE);

  printf(">>Exam 1 is: %s n", read_msg);

   close (second_pipe[READ_END]);

  // // TODO: read the message from the second pipe

}

/**********************************************************

 *       respond_to_the_rating           *

 * Reads the message from the first process and returns  *

 * the new message with the student's response to the   *

 * first process.                     *

 *********************************************************/

void respond_to_the_rating(int *first_pipe, int *second_pipe) {

  char write_msg[BUFFER_SIZE];

  char read_msg[BUFFER_SIZE];

  close (second_pipe[READ_END]);

  close (first_pipe[WRITE_END]);

  //printf("Child is responding...n");

  read(first_pipe[READ_END], read_msg, BUFFER_SIZE);

  printf("tChild Read from pipe: %s n", read_msg);

  close (first_pipe[READ_END]);

  write(second_pipe[WRITE_END], write_msg,

     strlen(write_msg)+1);

   printf("tChild wrote...: %s n", write_msg);

  close (second_pipe[WRITE_END]);

  // TODO: read the student's response from the first pipe

  // TODO: write the new message to the second pipe

}