Interactive C program : To create and update records

Here is an interactive C program written by me to create and update records in a txt file

/* program to create a text file   and update records  */

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include <dirent.h>
int main(void)
{

    FILE *fp;   /* file pointer*/
    char fName[30];
    char name[30];
    int age=0, SrNo=0,SrNo2=0,count_lines=0;
    char  qualification[20];
    char action,en,ch,c;

    A: printf("Type 'N' to create a new file and enter records\n");
    printf("Type 'U' to read/update/modify records in an existing file\n");
    scanf("%s",&action);
    if(action=='N')
    { //start of option if
        printf("Enter file name with .txt extension to create :");
        scanf("%s",fName);

        /*creating (open) a file, in “w”: write mode*/
        fp=fopen(fName,"w");
        /*check file created or not*/
        if(fp==NULL)
        {
        printf("File does not created!!!");
        exit(0); /*exit from program*/
        }

        //printf("\nFile created successfully.\n");
        printf("Start entering students records\n");
    // printf("Finally type e to exit or any other character to continue adding more records\n");
        while(en !='e')
        {

            printf("\nEnter (space separated) student's name, age and qualification \n");

            scanf("%s", name);
            SrNo++;
            fprintf(fp, "Roll No.%d  Name  :%s\t",SrNo, name);

            //printf("Enter student's age\n");

            scanf("%d", &age);

            fprintf(fp, "Age  :%d\t", age);

            // printf("Enter students qualification\n");

            scanf("%s", &qualification);

            fprintf(fp, "Qualification  :%s\n", qualification);

            printf("Type e to exit or any other char to add more records  ");
            //en = getchar();
            scanf("%s",&en);
            if(en== 'e')
            {   printf("\nFile created and records saved successfully.\n");
            break;
            }
        }
        fclose(fp);
    }  //end of option if
     else if(action=='U')
  {   //start of option if
          DIR *p;
            struct dirent *pp;
            p = opendir(".");

            if (p != NULL)
            {
                while ((pp = readdir (p))!=NULL)
                {
                    int length = strlen(pp->d_name);
                    if (strncmp(pp->d_name + length - 4, ".txt", 4) == 0)
                     {
                        puts (pp->d_name);
                     }
                }

                (void) closedir (p);
            }

            printf("\n1] Enter filename to read, from the above list of files\n");
            printf("2] Enter filename to add new records, from the above list of files\n");
            printf("3] Enter filename to delete a record, from the above list of files\n");
            printf("4] Enter filename to replace a record, from the above list of files\n");
            printf("5] Exit\n");

 ////////////////////////////////////////////////////////////////////////////////////////////////////////////

            while(1)
    {  //start of main while
                printf("\nEnter your choice : ");

                scanf("%d", &ch);

                switch (ch)
            {   //start of switch
                case 1:
                     printf("Enter the filename to be opened \n");

                     scanf("%s", fName);

                    /*  open the file for reading */

                    fp = fopen(fName, "r");

                    if (fp == NULL)

                    {

                        printf("Sorry this file does not exist !!, cannot open file \n");

                        exit(0);

                    } //end of if

                    c = fgetc(fp);

                    while (c != EOF)

                    { // start of 2nd while

                    printf ("%c", c);

                    c = fgetc(fp);

                    } //end of 2nd while

                    fclose(fp);
                    break;    // eo case 1

                case 2:
                    printf("Enter the filename to be opened and new record to be added\n");

                     scanf("%s", fName);

                    /*  open the file for reading */

                    fp = fopen(fName, "r");

                    if (fp == NULL)

                    {

                        printf("Cannot open file \n");

                        exit(0);

                    } //end of if
                    c=getc(fp);
                        while (c != EOF)

                    { //start of while

                            //Count whenever new line is encountered

                            if (c == '\n')

                            {

                                count_lines = count_lines + 1;

                            }

                            //take next character from file.

                            c = getc(fp);

                    } // end of while

                        fclose(fp); //close file.
                    SrNo2= count_lines;

                  fp=fopen(fName,"a");
                    /*check file created or not*/
                    if(fp==NULL)
                    {
                        printf("File not created!!!");
                        exit(0); /*exit from program*/
                    }

                    //printf("\nFile created successfully.\n");
                    printf("Start entering students records\n");
                    // printf("Finally type e to exit or any other character to continue adding more records\n");

                    while(en !='e')
                {

                    printf("\nEnter (space separated) student's name, age and qualification \n");

                    scanf("%s", name);
                    SrNo2++;
                    fprintf(fp, "Roll No.%d  Name  :%s\t",SrNo2, name);

                    //printf("Enter student's age\n");

                    scanf("%d", &age);

                    fprintf(fp, "Age  :%d\t", age);

                    // printf("Enter students qualification\n");

                    scanf("%s", &qualification);

                    fprintf(fp, "Qualification  :%s\n", qualification);

                    printf("Type e to exit or any other char to add more records  ");
                    //en = getchar();
                    scanf("%s",&en);
                    if(en== 'e')
                    {   printf("\nFile created and records updated successfully.\n");
                        //break;
                    }
            }
        fclose(fp);


                case 3:




                case 4:



                case 5:
                    exit(0);
                default:
                    printf("Wrong choice entered !! please try again\n");


            } // end of switch

    } //eo while
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////
     } //eo option if
     else
     {
         printf("Incorrect option entered, please try again\n");
         goto A;

     }
       
   return 0;

}