Demo Project

#include<stdio.h>
#include<conio.h>
 struct student
 {
 int rlno;
 char na[20];
 }; //structure for student data

struct student stu; //global variable for structure

//Function to recieve value of structure

void getdata()
 {
 printf("\n Enter Roll Num ");
 scanf("%d",&stu.rlno);
 printf("\n Enter Name ");
 scanf("%s",stu.na);
 }
 //function to display values of structure

void showdata()
 {
 // printf("\n Name is %s ",stu.na);
 // printf("\n Roll Num is %d ",stu.rlno);
 printf("\n%d\t\t%s\n",stu.rlno,stu.na);
 }

 void main()
 {
 int ch; // var for choice
 int choice;
 int rl;
 FILE *fp, *fp1;//var to open a file
 while(choice!=5)
 {
 clrscr();
 printf("\n 1. Add data ");
 printf("\n 2. List Records ");
 printf("\n 3. Delete Record ");
 printf("\n 4. Modify Record ");
 printf("\n 5. Quit");
 printf("\n Enter your choice ");
 scanf("%d",&choice);
 switch(choice)
 {
 case 1:
 fp=fopen("stud.txt","a"); //openning a file
 while(ch!=0)//loop
 {
 getdata();//getting data
 fwrite(&stu,sizeof(stu),1,fp);//writing to a file
 printf("\n Press 1 to add more, 0 to quit ");//prompt the user for cont...
 scanf("%d",&ch);
 }
 fclose(fp);//closing a file
 break;
 case 2:
 fp=fopen("stud.txt","r"); //reopening a file
 printf("\n Roll Num\t\tName");
 printf("\n======================================\n");
 while(fread(&stu,sizeof(stu),1,fp)==1)//loop for reading data
 {
 showdata();//display a data
 }
 fclose(fp);//closing a file
 getch();
 break;
 case 3:
 fp=fopen("stud.txt","r");
 fp1=fopen("temp.txt","a");
 printf("\n Enter rollnum u wanna delete ");
 scanf("%d",&rl);
 while(fread(&stu,sizeof(stu),1,fp)==1)
 {
 if(stu.rlno==rl)
 {
 printf("\n Record found ");
 showdata();
 printf("\n Press any Key to cont...");
 getch();
 }
 else
 {
 fwrite(&stu,sizeof(stu),1,fp1);
 }
 }
 fclose(fp);
 fclose(fp1);
 remove("stud.txt");
 rename("temp.txt","stud.txt");
 break;
 case 4:
 fp=fopen("stud.txt","r");
 fp1=fopen("temp.txt","a");
 printf("\n Enter rollnum u wanna Modify ");
 scanf("%d",&rl);
 while(fread(&stu,sizeof(stu),1,fp)==1)
 {
 if(stu.rlno==rl)
 {
 printf("\n Record found ");
 showdata();
 printf("\n Press any Key to enter new Values");
 getch();
 getdata();
 fwrite(&stu,sizeof(stu),1,fp1);
 }
 else
 {
 fwrite(&stu,sizeof(stu),1,fp1);
 }
 }
 fclose(fp);
 fclose(fp1);
 remove("stud.txt");
 rename("temp.txt","stud.txt");
 break;
 case 5:
 printf("\n Thanks for using this software ");
 getch();
 break;
 default:
 printf("\n Invalid Option ");
 getch();
 }//switch
 }//while
 }