c++:reading from file/parse string - c++

Question

I am currently working on a program, where the user of the program is required to input username and password, and the program will do the search and see if there is such user, if it exists, then proceeding to a screen with further options, or reenter the username.
The username.txt files that stores the username and password includes the following data:(first column is username, and second is password)
john,abc
marry,cde
admin,admin
joseph,1234
My code is as follows, but it doesnt work, after i input username and password, the programs automatically closes. Can you help me with it? Is there something wrong with my parsing the string into 2?
#include<iostream>
#include<fstream>
#include<sstream>
#include<string>
#include<math.h>
#include<stdio.h>
using namespace std;
void printoptionsadmin(){
cout << "Please select an option:" << endl;
cout << "1.Sell Stock\n2.Buy stock\n3.Inquiry\n4.Logout\n5.Shutdown" << endl;
}
void printoptions(){
cout << "Please select an option:" << endl;
cout << "1.Sell Stock\n2.Buy stock\n3.Inquiry\n4.Logout" << endl;
}
void main()
{
cout << "Please login." << endl;
stop:
string usertype;//user input
string passtype;//user input
string line;
string manager = "admin";
string managerp = "admin";
string user;//read from file
string pass;//read from file
ifstream openfile("username.txt");
cout << "Enter your username:";
cin >> usertype;
cout << "Enter your password:";
cin >> passtype;
bool found = false;
while (found&&getline(openfile, line))
{
stringstream iss(line);
getline(iss, user, ',');
getline(iss,pass);
if (usertype == manager && passtype == managerp)//admin login
{
void printoptionsadmin();
found = true;
break;
}
else if (usertype== user && passtype== pass)//regular login
void printoptions();
else
{
cout << "Invalid username or password, please start over." << endl;
goto stop;//going back to login screen
}
openfile.close();
}
}

Answer 1

I altered your code a bit, you messed up the found, plus i removed the goto, also you don't have to explicitly close the file, it is closed when the scope is left(RAAI).
I suggest you to add some checks to your code (file ok? read of line ok? ...)
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
using namespace std;
static const string PASSWORD_FILE("username.txt");
static const string MANAGER_USER = "admin";
static const char DELIM = ',';
void printoptionsadmin() {
cout << "Please select an option:" << endl;
cout << "1.Sell Stock\n2.Buy stock\n3.Inquiry\n4.Logout\n5.Shutdown"
<< endl;
}
void printoptions() {
cout << "Please select an option:" << endl;
cout << "1.Sell Stock\n2.Buy stock\n3.Inquiry\n4.Logout" << endl;
}
string login() {
ifstream passwordFile(PASSWORD_FILE);
string usertype; //user input
string passtype; //user input
cout << "Enter your username:";
cin >> usertype;
cout << "Enter your password:";
cin >> passtype;
for (string userPasswordLine; getline(passwordFile, userPasswordLine);) {
stringstream ss(userPasswordLine);
string user, password;
getline(ss, user, DELIM);
getline(ss, password, DELIM);
if (user == usertype && password == passtype) {
return user;
} // if
} // for
return "";
}
int main() {
cout << "Please login." << endl;
string loggedInUser;
while ((loggedInUser = login()) == "") {
cerr << "Login failed" << endl;
} // while
if (loggedInUser == MANAGER_USER) {
printoptionsadmin();
} else {
printoptions();
} // else
return 0;
}

Answer 2

Each getline() without third parameter will read a new line and it will provide you something that you are not needed here.
So use " " white space as the delimiter in getline() function instead of default "\n".
Also another thing is your while loop condition is always false since found is initialized to false. So it will not go inside while loop
Here is the logic you needed,
bool found = false;
while (found&&getline(openfile, line))
bool found = false;
std::string delimiter = ",";
while (getline(openfile, line, " "))//To read upto each " "(white space instead of next line(\n is default third parameter)
{
/* Splitting the UserName & Password using ','*/
user = line.substr(0, line.find(delimiter));
pass = line.substr(line.find(delimiter)+1, -1);
if (usertype == manager && passtype == managerp)//admin login
{
void printoptionsadmin();
found = true;
break;
}
else if (usertype== user && passtype== pass)//regular login
void printoptions();
else
{
cout << "Invalid username or password, please start over." << endl;
goto stop;//going back to login screen
}
openfile.close();
}