Emergency! Can anybody help me?

I'm writing a program that  can let a user input a student record at a time (including name, ID, and department number) until the user wants to stop. In the program I wrote before, I used a linked list to store the information in program, but I want to modify it, so that the information will be stored in an ASCII file. How can I do it? Can anybody help me? Thanks in advance!

Here is the program I wrote:

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

typedef enum  
{
      Math=1, Engl, Phys, Chem, Hist, Info
} departNum;

typedef struct   StudentData
{
      char name[51];  
      unsigned short  studentID;  
      departNum depar;  
      struct StudentData *next;

} Student;

Student *get_student(void);

void print_StudentData( Student* first);

int main(void)
{
      Student *firstLink;

      firstLink = NULL;  

      firstLink = get_student();

      print_StudentData( firstLink);

      return (0);
}

   Student *get_student(void)
   {
         Student *newLink, *firstLink, *lastLink;
         int choose;

         newLink = firstLink = lastLink = NULL;  

         printf("\nPlease enter 1 to add a student data or enter 2 to exit :");
         scanf("%d", &choose);

         while ( choose == 1)  
         {
               newLink = (Student*) malloc(sizeof(Student));

                  printf("\nPlease enter a new Student Name : ");
                  gets(newLink->name);
                  gets(newLink->name);

                  printf("Please enter a new Student ID number : ");  
                  scanf("%d", &(newLink->studentID));
            
                  printf("Please enter a Department Number\nMath=1, English=2, Physics=3, Chemistry=4, History=5, Infomation=6 : ");
               scanf("%d", &(newLink->depar));

                                   newLink->next = NULL;

               if (!firstLink)
               {
                     firstLink = lastLink = newLink;
               }
               else
               {
                     lastLink->next = newLink;
                     lastLink = newLink;
               }

               printf("\nPlease enter 1 to add a student data or enter 2 to exit :");
                  scanf("%d", &choose);

         }

            return firstLink;

   }


   void print_StudentData( Student *firstLink)
   {
         Student *currLink;
        
                   char* departmentName[] = {"", "Math", "English", "Physics", "Chemistry", "History", "Information"};

         currLink = firstLink;

        
               printf("\n\nName\t\tID\tDepartment\n");
               printf("----------------------------------------------------\n");

               while(currLink)
               {
                     printf("%s", currLink->name);
                     printf("\t\t%d", currLink->studentID);
                  printf("\t%s\n",departmentName[currLink->depar]);

                  currLink = currLink->next;

            }

   }