Using a Pipe file to transfer names

Question

I have 3 ".c" files called pre, sort and pipe. Pre takes a user input of names and GPA from a console. If the GPA is greater than or equal to 3.0, the name is stored into a struct.

Here's the pre.c file:

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

struct student{
  char temp_name[50];
  char names[50];
};

int main()
{
  int read_index = 0;
  float check_gpa;

  struct student data[read_index];

  printf("Enter student name and GPA: \n");
  scanf("%s %f\n", data[read_index].temp_name, &check_gpa);
  read_index++;

  while(scanf("%s %f\n", data[read_index].temp_name, &check_gpa) != EOF)
       {
         if (check_gpa >= 3.0)
            {
              strcpy(data[read_index].names, data[read_index].temp_name);
              read_index++;
            }
       }

  return 0;
}

The pipe file links the pre and sort files so that data from pre is sent to sort.

Here is the pipe.c file:

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/types.h>
#include<string.h>
#include<sys/wait.h>

int main()
{
  char *args[] = {"./sort", NULL};
  char *argv[] = {"./pre", NULL};

  int pipe_end[2];
  int pipe_id;
  pipe(pipe_end);

  if (pipe(pipe_end)==-1) // Check for pipe functionality
    {
        perror("Pipe Failed");
        return 1;
    }

  pipe_id = fork();

  if (pipe_id < 0) //Check for fork functionality
  {
    printf("Fork failed");
    return 1;
  }
  else if(pipe_id == 0)//Child
  {
    close(pipe_end[0]);
    dup(pipe_end[0]);
    execvp(argv[0], argv);
  }
  else //Parent
  {
    wait(NULL);
    close(pipe_end[1]);
    dup2(pipe_end[1], 0);
    close(pipe_end[0]);
    execvp(args[0], args);

  }

  return 0;
}

The sort file takes names from a struct array and sorts them alphabetically and prints them to the console. And this is where the problem starts, because when I run the pipe file i get to enter names and GPA's But when ever I initiate an EOF (which is required and cannot change) by pressing Ctrl+D, I'm expecting the strings to be sent over to sort and displayed alphabetically, however this doesn't happen.

Here's the sort.c file:

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/types.h>
#include<string.h>
#include<sys/wait.h>

struct student{
  char temp_name[50];
  char names[50];
};

int main()
{
  int print_index1 = 0,
      print_index2,
      read_index,
      SIZE;

struct student data[print_index1];

SIZE = print_index1;


printf("Students with GPA's greater than or equal to 3.0, listed in alphabetical order:\n ");
for(print_index1 = 0; print_index1 < SIZE; print_index1++)
   {

            for(print_index2 = print_index1 + 1; print_index2 < SIZE; print_index2++)
               {
                  if(strcmp(data[print_index1].names, data[print_index2].names) > 0)
                    {
                      strcpy(data[print_index1].temp_name, data[print_index2].names);
                      strcpy(data[print_index2].names, data[print_index1].names);
                      strcpy(data[print_index1].names, data[print_index1].temp_name);

                    }
                }

      printf("%s\n", data[print_index1].names);
    }

  return 0;
}

I've tested both files independently with user input and they worked. But a new problem has showed up, if you look at the sort file and notice I have a while loop that takes a for loop condition that I thought made sense> It worked a week ago but now it doesn't (unless it was a fluke). But that's my dilemma, I can't seem to get user input from "pre.c" over to "sort.c" I would really appreciate some help. I also think the while loop in the "sort.c" file is causing an issue with printing the names.