C Projects Source Code - Telecom Billing System

//-PRORAMMING MADE SIMPLE
#include<stdio.h>
#include<conio.h>
#include<ctype.h>
#include<windows.h>
#include<stdlib.h>
struct subscriber
{
char phonenumber[20];
char name[50];
float amount;
}s;
void addrecords();
void listrecords();
void modifyrecords();
void deleterecords();
void searchrecords();
void payment();
char get;
int main()
{  int password;
   int phonenumber;
   char choice;



   system("cls");

   printf("\n\n\n\n\n\n\n\n\n**************************************************************");
   printf("\n\t\t------WELCOME TO THE TELECOM BILLING MANAGEMENT SYSTEM---");
   printf("\n\t\t****************************************************************");
   Sleep(2000);
   getch();
    system("cls");
   while (1)
   {
      system("cls");
      printf("\n Enter\n A : for adding new records.\n L : for list of records");
      printf("\n M : for modifying records.\n P : for payment");
      printf("\n S : for searching records.");
      printf("\n D : for deleting records.\n E : for exit\n");
      choice=getche();
      choice=toupper(choice);
      switch(choice)
      {
         case 'P':
            payment();break;
         case 'A':
            addrecords();break;
         case 'L':
            listrecords();break;
         case 'M':
            modifyrecords();break;
         case 'S':
            searchrecords();break;
         case 'D':
            deleterecords();break;
         case 'E':
            system("cls");
            printf("\n\n\t\t\t\tTHANK YOU");
            printf("\n\n\n\n\n:\n\tFOR USING OUR SERVICE");
            Sleep(2000);
            exit(0);
            break;
         default:
            system("cls");
            printf("Incorrect Input");
            printf("\nAny key to continue");
            getch();
      }
   }
}
void addrecords()
{
   FILE *f;
   char test;
   f=fopen("c:/file.ojs","ab+");
   if(f==0)
   {   f=fopen("c:/file.ojs","wb+");
      system("cls");
      printf("please wait while we configure your computer");
      printf("/npress any key to continue");
      getch();
   }
   while(1)
   {
      system("cls");
      printf("\n Enter phone number:");
      scanf("%s",&s.phonenumber);
      printf("\n Enter name:");
      fflush(stdin);
      scanf("%[^\n]",&s.name);
      printf("\n Enter amount:");
      scanf("%f",&s.amount);
      fwrite(&s,sizeof(s),1,f);
      fflush(stdin);
      system("cls");
      printf("1 record successfully added");
      printf("\n Press esc key to exit, any other key to add other record:");
      test=getche();
      if(test==27)
         break;
   }
   fclose(f);
}
void listrecords()
{
   FILE *f;
   int i;
   if((f=fopen("c:/file.ojs","rb"))==NULL)
      exit(0);
   system("cls");
   printf("Phone Number\t\tUser Name\t\t\tAmount\n");
   for(i=0;i<79;i++)
      printf("-");
   while(fread(&s,sizeof(s),1,f)==1)
   {
      printf("\n%-10s\t\t%-20s\t\tRs. %.2f /-",s.phonenumber,s.name,s.amount);
   }
   printf("\n");
   for(i=0;i<79;i++)
      printf("-");

fclose(f);
getch();
}
void deleterecords()
{
   FILE *f,*t;
   int i=1;
   char phonenumber[20];
   if((t=fopen("c:/temp.ojs","w+"))==NULL)
   exit(0);
   if((f=fopen("c:/file.ojs","rb"))==NULL)
   exit(0);
   system("cls");
   printf("Enter the phone number to be deleted from the Database");
   fflush(stdin);
   scanf("%[^\n]",phonenumber);
   while(fread(&s,sizeof(s),1,f)==1)
   {
      if(strcmp(s.phonenumber,phonenumber)==0)
      {       i=0;
         continue;

      }
      else
         fwrite(&s,sizeof(s),1,t);
   }
   if(i==1)
   {       system("cls");
      printf("Phone number \"%s\" not found",phonenumber);
      remove("c:/file.ojs");
      rename("c:/temp.ojs","c:/file.ojs");
      getch();
      fclose(f);
      fclose(t);
      main();
   }
   remove("c:/file.ojs");
   rename("c:/temp.ojs","c:/file.ojs");
   system("cls");
   printf("The Number %s Successfully Deleted!!!!",phonenumber);
   fclose(f);
   fclose(t);
   getch();
}
void searchrecords()
{
   FILE *f;
   char phonenumber[20];
   int flag=1;
   f=fopen("c:/file.ojs","rb+");
   if(f==0)
      exit(0);
   fflush(stdin);
   system("cls");
   printf("Enter Phone Number to search in our database");
   scanf("%s", phonenumber);
   while(fread(&s,sizeof(s),1,f)==1)
   {
      if(strcmp(s.phonenumber,phonenumber)==0)
      {  system("cls");
         printf(" Record Found ");
         printf("\n\nPhonenumber: %s\nName: %s\nAmount: Rs.%0.2f\n",s.phonenumber,s.name,s.amount);
         flag=0;
         break;
      }
      else if(flag==1)
      {  system("cls");
         printf("Requested Phone Number Not found in our database");
      }
   }
   getch();
   fclose(f);
}
void modifyrecords()
{
   FILE *f;
   char phonenumber[20];
   long int size=sizeof(s);
   if((f=fopen("c:/file.ojs","rb+"))==NULL)
      exit(0);
   system("cls");
   printf("Enter phone number of the subscriber to modify:");
   scanf("%[^\n]",phonenumber);
   fflush(stdin);
   while(fread(&s,sizeof(s),1,f)==1)
   {
      if(strcmp(s.phonenumber,phonenumber)==0)
      {
         system("cls");
         printf("\n Enter phone number:");
         scanf("%s",&s.phonenumber);
         printf("\n Enter name: ");
         fflush(stdin);
         scanf("%[^\n]",&s.name);
         printf("\n Enter amount: ");
         scanf("%f",&s.amount);
         fseek(f,-size,SEEK_CUR);
         fwrite(&s,sizeof(s),1,f);
         break;
      }
   }
   fclose(f);
}
void payment()
{
   FILE *f;
   char phonenumber[20];
   long int size=sizeof(s);
   float amt;
   int i;
   if((f=fopen("c:/file.ojs","rb+"))==NULL)
      exit(0);
   system("cls");
   printf("Enter phone number of the subscriber for payment");
   scanf("%[^\n]",phonenumber);
   fflush(stdin);
   while(fread(&s,sizeof(s),1,f)==1)
   {
      if(strcmp(s.phonenumber,phonenumber)==0)
      {
         system("cls");
         printf("\n Phone No.: %s",s.phonenumber);
         printf("\n Name: %s",s.name);
         printf("\n Current amount: %f",s.amount);
         printf("\n");
         for(i=0;i<79;i++)
            printf("-");
         printf("\n\nEnter amount of payment :");
         fflush(stdin);
         scanf(" %f",&amt);
         s.amount=s.amount-amt;
         fseek(f,-size,SEEK_CUR);
         fwrite(&s,sizeof(s),1,f);
         break;
      }
   }
   system("cls");
   printf("THANK YOU %s FOR YOUR TIMELY PAYMENTS",s.name);
   getch();
   fclose(f);
}