Telephone Billing Management System in C

In this article I would like to share with you a program that I wrote a long time ago using C language I called this program Telephone Billing Management System in C. I am using Turbo C 2.0 in DOS in in writing this program it saves, computes the billing statements of the consumer of a telephone company it store the record in a flat file also know as text file.

Feel free to use my code in your programming projects at school or work.  If you have some questions please send me an email at jakerpomperada@gmail.com and jakerpomperada@yahoo.com.

People here in the Philippines can reach me at my mobile number 09173084360.

Thank you very much and Happy Programming.

Sample Program Output

Program Output

#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 phonenumber;

char choice;

while (1)

{

system("cls");

printf("\n     **********************************************");

printf("\n    ****  TELEPHONE BILLING MANAGEMENT SYSTEM  ****");

printf("\n    ***********************************************");

  printf("\n");

      printf("\n\t A : Adding new records.\n \t L : Listing of records");

printf("\n\t M : Modifying records.\n \t P : Payments");

printf("\n\t S : Searching records.");

printf("\n\t D : Deleting records.\n\t E : Exit Program\n");

  printf("\n");

  printf("\n\t PLEASE SELECT THE LETTERS ONLY " );

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("data.dat","ab+");

if(f==0)

{   f=fopen("data.dat","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("data.dat","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\t $. %.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("temp.dat","w+"))==NULL)

exit(0);

if((f=fopen("data.dat","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("data.dat");

rename("temp.dat","data.dat");

getch();

fclose(f);

fclose(t);

main();

}

remove("data.dat");

rename("temp.dat","file.dat");

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("data.dat","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: $ %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("data.dat","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("data.dat","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=(amt-s.amount);

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);

}