Hello, am working on a program like a database
Here's the code:
#include <cstdlib>
#include <iostream>
using namespace std;
void addclient(void);
void choice (void);
typedef struct client{
int number;
char name[35];
char gender[8];
char address[50];
char phoneno[15];
char mobileno[10];
struct client *next;
} client;
client *firstnode,*currentnode,*newnode;
int clientid = 0;
int main(int argc, char *argv[])
{
int count;
int x;
FILE *datafile;
char *filename = "client.dat";
char ch;
firstnode = NULL;
datafile = fopen(filename,"r");
if(datafile)
{
currentnode = firstnode;
while(1)
{
fread(currentnode,sizeof(struct client),1,datafile);
if(currentnode->next == NULL)
break;
currentnode->next = newnode;
currentnode = newnode;
}
fclose(datafile);
clientid = currentnode->number;
}
do
{
fflush(stdin);
cout<<"\nWelcome To Mobile service Database"<<endl;
cout<<"-- -----------------------------"<<endl;
cout<<"1 - Add a new Client"<<endl;
cout<<"-- -----------------------------"<<endl;
cout<<"Q - Save and quit\n";
cout<<"\tYour choice:";
ch = getchar();
ch = toupper(ch);
switch(ch)
{
case '1':
cout<<"Add a new Client\n";
fflush(stdin);
addclient();//call addNewcontact function
break;
case 'Q':
cout<<"Save and quit\n";
default:
break;
}
}
while(ch != 'Q');
/*
* Save the records to disk
*/
currentnode = firstnode;
if(currentnode == NULL)
return(0); /*no data to write*/
datafile = fopen(filename,"w"); /*open file to write*/
if(datafile == NULL)
{
cout<<"Error writing to " <<filename;
return(1);
}
/* Write each record to disk*/
while(currentnode != NULL)
{
fwrite(currentnode,sizeof(struct client),1,datafile);
currentnode = currentnode->next;
}
fclose(datafile); /*closes data file*/
return(0);
}
void addclient(void)
{
newnode = (struct client *)malloc(sizeof(struct client));
if(firstnode==NULL)
firstnode = currentnode = newnode;
else
{
currentnode = firstnode;
while(currentnode->next != NULL)currentnode = currentnode->next;
currentnode->next = newnode;
currentnode = newnode;
}
clientid++;
cout<<"Client ID " <<clientid<<" ";
currentnode->number = clientid;
cout<<"\n";
cout<<"Enter Client name: ";
cin.getline(currentnode->name,35);
cout<<"Enter Client gender: ";
cin>>currentnode->gender;
cout<<"Enter Client address: ";
cin>>currentnode->address;
cout<<"Enter Phone Number: ";
cin>>currentnode->phoneno;
cout<<"Enter Mobile Number: ";
cin>>currentnode->mobileno;
cout<<"staff added!\n";
currentnode->next = NULL;
}when i run it, it works well, but when i close the program and open the text file
and then rerun the program, the program crash
any help PLEASE
thanks