MAHAFILE.c

// A menu driven program for elementry database management
#include <stdio.h>

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

void main()
{
	FILE *fp, *ft;
	char another, choice;
	struct emp
	{
		char name[40];
		int age;
		float bs;
	};
	struct emp e;
	char empname[40];
	long int recsize;

	fp = fopen("EMP.DAT", "rb+");
	if (fp == NULL)
	{
		fp = fopen("EMP.DAT", "wb+");

		if (fp == NULL)
		{
			puts("Cannot Open File....");
			exit(1);
		}
	}
	recsize = sizeof(e);

	while (1)
	{

		gotoxy(30, 10);
		printf("1.Add Records");
		gotoxy(30, 12);
		printf("2List Records");
		gotoxy(30, 14);
		printf("3.Modify Records");
		gotoxy(31, 16);
		printf("4.Delete Records");
		gotoxy(30, 20);
		printf("Your choice:\n");

		fflush(stdin);
		choice = getche();
		switch (choice)
		{
		case 1:

			fseek(fp, 0, SEEK_END);
			another = 'y';
			while (another == 'y')
			{
				printf("\nEnter name,age and basic salary:");
				scanf("%s %d %f", e.name, &e.age, &e.bs);
				fwrite(&e, recsize, 1, fp);
				printf("\nAdd another Record (y/n):");
				fflush(stdin);
				another = getche();
			}
			break;
		case 2:

			rewind(fp);

			while (fread(&e, recsize, 1, fp) == 1)
				printf("\n%s %d %f", e.name, e.age, e.bs);
			break;

		case 3:

			another = 'y';
			while (another == 'y')
			{
				printf("\nEnter name of employee to modify");
				scanf("%s", empname);

				rewind(fp);
				while (fread(&e, recsize, 1, fp) == 1)
				{
					if (strcmp(e.name, empname) == 0)
					{
						printf("\nEnter new name, age and bs:\n");
						scanf("%s %d %f", e.name, &e.age, &e.bs);
						fseek(fp, -recsize, SEEK_CUR);
						fwrite(&e, recsize, 1, fp);
						break;
					}
				}
				printf("\nModify another record(y/n)");
				fflush(stdin);
				another = getche();
			}
			break;

		case 4:
			another = 'y';
			while (another == 'y')
			{
				printf("Enter name of employee to delete:");
				scanf("%s", empname);

				ft = fopen("TEMP.DAT", "wb");
				rewind(fp);
				while (fread(&e, recsize, 1, ft) == 1)
				{
					if (strcmp(e.name, empname) != 0)
						fwrite(&e, recsize, 1, ft);
				}
				fclose(fp);
				fclose(ft);
				remove("EMP.DAT");
				rename("TEMP.DAT", "EMP.DAT");

				fp = fopen("EMP.DAT", "rb+");

				printf("\nDelete another record(y/n):");
				fflush(stdin);
				another = getche();
			}
			break;
		case 0:
			fclose(fp);
			exit(0);
		}
	}
}