Can someone please help - my program compiles but I get a assertion error

**mikebaily** · May 14th, 2003, 05:58 AM

I have this code which compiles but I get an assertion error when I run the application:

It is to do with the file I have decalred f1. I need a variable for a file that will allow me to read and write to it because I am manipulating the file position. I have listed my code below.

Can someone please help.

Code:

#include <windows.h>
#include <conio.h>
#include <iostream>
#include <stdlib.h>
#include <string>
#include <fstream>

using namespace std;

struct PAYROLL {
	char fname[20];
	char lname[20];
	float pay;
	char password[20];
}x;


void enter_password();
void clear_screen();
void MakeArrayBlank();
char Name[20];
char LName[20];

string FileName;

float payment;
bool RunMore;
HKEY hKey;
char szBuf[10];
bool RunOnce;
char val[10];
char c;
char pass[10];
int counter;

fstream f1 (FileName.c_str(),ios::in || ios::app);

	  
bool Isthere =false;

void main ()
{


  DWORD dwSize=0;
  DWORD dwValue;
  DWORD valType =0;
  DWORD dwLen = sizeof(val);

  f1.clear();
  strcpy(Name,"");
  strcpy(LName,"");
  strcpy(x.fname,"");
  strcpy(x.lname,"");
  strcpy(x.password,"");

  x.pay=0;


  
  int choice;
  int counter=0;

  char password[20];
   
//open registry to look for a key

  strcpy(szBuf,"true");

  dwSize = sizeof(dwValue);


  if(::  RegOpenKeyEx(HKEY_LOCAL_MACHINE,
	  "system",
	  0,
	  KEY_SET_VALUE | KEY_QUERY_VALUE,
	  &hKey)==ERROR_SUCCESS)
  
     long rc = RegQueryValueEx(hKey,
				"PayRoll Flag",
				NULL,
				&valType,
				reinterpret_cast<unsigned char *>(val),
				&dwLen);
  

  if (strcmp (val,"true") ==0)
	   RunOnce = false;
   else
	   RunOnce = true;

   ::RegCloseKey(hKey);

   cout << RunOnce;

   if (RunOnce == true) //write the key if first time it is run
   {
		
	  if(::  RegOpenKeyEx(HKEY_LOCAL_MACHINE,
	  "system",
	  0,
	  KEY_SET_VALUE | KEY_QUERY_VALUE,
	  &hKey)==ERROR_SUCCESS)
	  {
		  if (::RegSetValueEx(hKey,
			  "PayRoll Flag",
			  0,
			  REG_SZ,
			  (LPBYTE) szBuf,
			  strlen(szBuf) + 1))
		  {
			  ::RegCloseKey(hKey);
				return;
		  }
	  }

   }





  FileName = "c:/hello.dat";
  
  f1.open(FileName.c_str(),ios::app);
  f1.write((char*)&x,sizeof(x));
           //writes to disk
  f1.clear();
  f1.close();
  
  
  cout << "**************************************************";
  cout << "\n \n \n \n";
  cout << "Enter your first name : ";
  fflush(stdin);
  gets (x.fname);
  cout << "Enter your last name : ";
  fflush(stdin);
  gets (x.lname);
  
  strcpy(Name,x.fname);
  strcpy(LName,x.lname);


if (RunOnce == false)
{
  Isthere=false;
  f1.clear();
  f1.clear();
  f1.open(FileName.c_str(),ios::in); //opens file for reading
  f1.read((char*)&x,sizeof(x)); //reads file
 

  while (!f1.eof() || !Isthere==true)
  {
     if ((strcmp(x.fname,Name) == 0) && (strcmp(x.lname,LName) ==0))
	 {
		 Isthere=true;
		
	 }
    else
	 f1.read((char*)&x,sizeof(x));
  }

  f1.close();

  if ((Isthere == true) && (strcmp(x.password,"") !=0))
  {
     
	  f1.clear();
	  f1.open(FileName.c_str(),ios::in); //opens file for reading
      f1.read((char*)&x,sizeof(x)); //reads file

	   cout <<"\n" "\n" "\n" <<"Enter your password : ";
	  cin >> password;
     
      if ((strcmp(x.password,password) ==0)) 
	  {
	  clear_screen();
	  cout <<"x.password is : "  <<x.password <<endl;
	  cout <<"password is : " << password << endl;
	  cout <<"x.fname is : " << x.fname << endl;
	  cout <<"Name is : " << Name << endl;
	  cout <<"x.lname is : " << x.lname << endl;
	  cout <<"LName is : " << LName << endl;
	  _getch();
	  }
	
  
   else
   {
	 


	  if (Isthere==false)
	  {
         cout << "\n" <<"You must enter the correct password ";
	     cout << "\n" <<"You have 3 attempts";
         cin >> password;

		 counter = counter+1;
         if (counter==3) 
		 {
			 exit(1);
		 }
	  }
   }
  }
  else
	 {
	  cout <<"x.password is : "<< x.password;
	  cout <<"\n" "\n" "\n" "You must enter a password now : ";
	  cin >> x.password;
	  f1.clear();
      f1.open(FileName.c_str(),ios::app);
	  f1.write((char*)&x,sizeof(x)); //write file
cout <<"x.password is : " << x.password;	
  }
  
  
  
}

if (RunOnce == true)
{
enter_password();

f1.open(FileName.c_str(),ios::app);
f1.write((char*)&x,sizeof(x)); //write file
f1.clear();
f1.close();
cout << x.fname;
}

  Isthere=false;
 f1 << x.fname;
 f1 <<"Yo!!!";

 f1.open(FileName.c_str(),ios::in); //opens file for reading
 f1.read((char*)&x,sizeof(x)); //reads file		
 

clear_screen();

  do {

 //ERROR NEED WHILE LOOP TO FIND END OF FILE

  while (!f1.eof() && !Isthere==true)
  {
     cout <<x.fname;
	  if ((strcmp(x.fname,Name) == 0) && (strcmp(x.lname,LName) ==0))
	 {
		 Isthere=true;
	 }
    else
	 f1.read((char*)&x,sizeof(x));
  }

  f1.close();

  cout <<"******************************";
  cout <<"\n" <<"This session is for";
  cout <<"\n" <<x.fname <<" " << x.lname;
  cout <<"\n" "\n";

  cout  <<" \n "<< "1 : Enter Pay";
  cout << "\n "<<  "2 : Display your details";
  cout << "\n " << "3 : Change the path to install information";
  cout <<" \n " << "9 : Quits the program";
  cout <<"\n" "\n" "\n";

  cin >> choice;
  
  if (choice == 1) 
  {
	   
	  f1.open(FileName.c_str(),ios::app);

 cout <<"\n" << "Enter pay : " ;
 cin >> x.pay;

 f1.write((char*)&x,sizeof(x));
 f1.close();
 exit(1);//exit program - another fix would be to set choice to 9
  }

 else if (choice == 2)
 {	 
     Isthere = false;
	 clear_screen();
	
	 
		 if ((strcmp(x.fname,Name)==0) && (strcmp(x.lname,LName)==0))
		 {
            Isthere=true;
			 payment=x.pay;
	        strcpy(Name,x.fname);
			strcpy(LName,x.lname);
			fflush(stdin);
			cout <<"\n" <<"The following information is from disk";
            cout <<"\n" <<"**************************************************";
            cout <<"\n \n" <<"Your name : " << Name<< " " <<LName;
           	cout <<"\n";
			cout <<"Your payment is : ";
			cout <<payment;
            cout <<"\n""\n""\n""\n";
			while (choice !=1)
			{
				cout<<"Enter 1 to return to the menu : ";
				cin >> choice;
					if (choice == 1)
					{
						clear_screen();
					}
			}

			
		 }
	
    
 }

 else if (choice ==3)
 {
	 cout <<"The installation path at the moment is : ";
	 cout <<FileName;
	 cout <<"Enter new installation path please :";
	 cin >> FileName;
	 cout <<"\n" "\n" "\n";
	 cout <<"The path has been changed to : ";
	 cout << FileName;
 }
 
 
  }
  while (choice !=9);
	 
  return;
}


void enter_password()
{
	clear_screen();

		cout << "Enter a password - max 10 characters";

		c=getch();

		while (c!='\r' && c!='\n' && counter!=10)
		{

			cout <<"*";
			c=getch();
			pass[counter] = c;
			counter++;
		}
        strcpy(x.password,pass);

		f1.open(FileName.c_str(),ios::in);
		f1.read((char*)&x,sizeof(x));

		Isthere=false;

		while(!f1.eof() || !Isthere==true)
		{
			if ((strcmp(x.fname,Name) == 0) && (strcmp(x.lname,LName) ==0))
			{
				Isthere=true;
				ios::pos_type mark = f1.tellg();
				f1.open(FileName.c_str(),ios::app);
				f1.write((char*)&x,sizeof(x));
				f1.clear();
				f1.seekg(mark);
				f1.close();

			}
		}


}

void clear_screen()
{
	system("CLS");
  
	return;
}

[ADMIN] Added code tags...

**Tom Frohman** · May 14th, 2003, 07:21 AM

The problem lies in this line.

fstream f1 (FileName.c_str(),ios::in || ios::app);

When I comment out the rest of the line
fstream f1;// (FileName.c_str(),ios::in || ios::app);

The program runs.

Also

FileName = "c:/hello.dat";

should be

FileName = "c:\\hello.dat";

**Paul McKenzie** · May 14th, 2003, 07:39 AM

Originally posted by Tom Frohman
Also
FileName = "c:/hello.dat";
should be
FileName = "c:\\hello.dat";

Nope. The filename given by the OP is perfectly valid.

In ANSI C and C++, the forward slash can be used as the directory seperator, regardless of what the underlying OS uses as a directory seperator. For standard I/O functions and stream classes, the forward slash is preferred, since it is universally accepted. Try it and you'll see it works perfectly.

Regards,

Paul McKenzie

**Tom Frohman** · May 14th, 2003, 08:16 AM

Originally posted by Paul McKenzie
Nope. The filename given by the OP is perfectly valid.

In ANSI C and C++, the forward slash can be used as the directory seperator, regardless of what the underlying OS uses as a directory seperator. For standard I/O functions and stream classes, the forward slash is preferred, since it is universally accepted. Try it and you'll see it works perfectly.

Regards,

Paul McKenzie

Well, you learn something new everyday.

**mikebaily** · May 14th, 2003, 09:56 AM

Thanks for your feedback guys. However when I comment out the line the program works but it does not create a file.

I used to use ifstream and ofstream and I got the program to read and write. But I need to manipulate the pointer position of the file and I have seen the bit of code that you had said to comment out in a book.

I could go back to using ifstream and ofstream but how do I manipulate the pointer of the file position because I want to overwrite records in this program.

Thanks in advance for your help.

**Andreas Masur** · May 14th, 2003, 11:35 AM

I just looked at the mentioned line...you are declaring a global variable named 'FileName'. At this point the variable does not contain anything. Then you are trying to create a global stream object named 'f1' and try to open the file with the filename stored in 'FileName'. However, at this point the filename was not set at this point. Later in your code you are explicitely trying to open the file by using the method 'open()'...

So...basically I would suggest to skip the first constructor call as mentioned by Tom...

**mikebaily** · May 14th, 2003, 12:19 PM

Hi Andreas when i comment out that code for some reason my program doesn't produce the .dat file

As mentioned in my previous post I used ofstream and ifstream and it read and wrote records but now it doesn't.

Why is this?

**Tom Frohman** · May 15th, 2003, 07:05 AM

I don't ever use streams but I was playing around with this program.

When I change

f1.open(FileName.c_str(),ios::app);

to

f1.open(FileName.c_str(),ios::out|ios::app);
,

it opens the file and writes to it. If I don't, it doesn't open the file and write to it.

It hangs up soon after this for me.
Like I say, I've never used streams don't know if I'm saying something ignorant or not.

Tom

**Andreas Masur** · May 15th, 2003, 10:09 AM

Originally posted by Tom Frohman
I don't ever use streams but I was playing around with this program.

When I change

f1.open(FileName.c_str(),ios::app);

to

f1.open(FileName.c_str(),ios:

ut|ios::app);
,

it opens the file and writes to it. If I don't, it doesn't open the file and write to it.

It hangs up soon after this for me.
Like I say, I've never used streams don't know if I'm saying something ignorant or not.

Tom

Well...'fstream' is the generic stream class which can be used for input and output files. Therefore you have to specify whether you want to read from a file or write to a file...so nothing ignorant here...

**mikebaily** · May 15th, 2003, 11:39 AM

Thanks Tom I can now write but cannot read from the file now.

I am using :

f1.open(Filename.c_str(),ios::in);
f1.read((char*)&x,sizeof(x);

any ideas?

**Tom Frohman** · May 15th, 2003, 12:24 PM

When I run it in debug mode it never gets past this loop.

while (!f1.eof() || !Isthere==true)
{
if ((strcmp(x.fname,Name) == 0) && (strcmp(x.lname,LName) ==0)) {
Isthere=true;

}else
f1.read((char*)&x,sizeof(x));
}

because once you find the name it sets isthere to true and doesn't read the next line. When it comes around again x.fname are the same as last time. It is caught in this loop forever.

You need to get rid of the else.
So that will eventually read the last line and f1.eof()=true and isthere=true on which it will exit the loop.
while (!f1.eof() || !Isthere==true)
{
if ((strcmp(x.fname,Name) == 0) && (strcmp(x.lname,LName) ==0)) {
Isthere=true;
}
f1.read((char*)&x,sizeof(x));

}

This happens several times in your code.

**mikebaily** · May 15th, 2003, 04:06 PM

Hi Tom,

The reason why it was looping was because there was no EOF - the file was not opened for reading.

I have new code it's still buggy as **** but it's working better.

Thanks for your help on this because you have been very helpful.

new code :

#include <windows.h>
#include <conio.h>
#include <iostream>
#include <stdlib.h>
#include <string>
#include <fstream>

using namespace std;

struct PAYROLL {
char fname[20];
char lname[20];
float pay;
char password[20];
}x;

void CheckNameOnFile();
void enter_password();
void clear_screen();
void MakeArrayBlank();
char Name[20];
char LName[20];

string FileName = "c:/hello.dat";

float payment;
bool RunMore;
HKEY hKey;
char szBuf[10];
bool RunOnce;
char val[10];
char c;
char pass[10];
int counter;

fstream f1;

bool Isthere =false;

void main ()
{

DWORD dwSize=0;
DWORD dwValue;
DWORD valType =0;
DWORD dwLen = sizeof(val);

f1.clear();
strcpy(Name,"");
strcpy(LName,"");
strcpy(x.fname,"");
strcpy(x.lname,"");
strcpy(x.password,"");

x.pay=0;

int choice;
int counter=0;

char password[20];

//open registry to look for a key

strcpy(szBuf,"true");

dwSize = sizeof(dwValue);

if(:: RegOpenKeyEx(HKEY_LOCAL_MACHINE,
"system",
0,
KEY_SET_VALUE | KEY_QUERY_VALUE,
&hKey)==ERROR_SUCCESS)

long rc = RegQueryValueEx(hKey,
"PayRoll Flag",
NULL,
&valType,
reinterpret_cast<unsigned char *>(val),
&dwLen);

if (strcmp (val,"true") ==0)
RunOnce = false;
else
RunOnce = true;

::RegCloseKey(hKey);

cout << RunOnce;

if (RunOnce == true) //write the key if first time it is run
{

if(:: RegOpenKeyEx(HKEY_LOCAL_MACHINE,
"system",
0,
KEY_SET_VALUE | KEY_QUERY_VALUE,
&hKey)==ERROR_SUCCESS)
{
if (::RegSetValueEx(hKey,
"PayRoll Flag",
0,
REG_SZ,
(LPBYTE) szBuf,
strlen(szBuf) + 1))
{
::RegCloseKey(hKey);
return;
}
}

}

f1.open(FileName.c_str(),ios:

ut | ios::app);
f1.write((char*)&x,sizeof(x));
//writes to disk
//f1.clear();
//f1.close();

cout << "**************************************************";
cout << "\n \n \n \n";
cout << "Enter your first name : ";
fflush(stdin);
gets (x.fname);
cout << "Enter your last name : ";
fflush(stdin);
gets (x.lname);

strcpy(Name,x.fname);
strcpy(LName,x.lname);

if (RunOnce == false)
{
Isthere=false;
f1.clear();
f1.clear();
f1.open(FileName.c_str(),ios::in|ios::app); //opens file for reading
f1.read((char*)&x,sizeof(x)); //reads file

while (!f1.eof() || !Isthere==true)
{
if ((strcmp(x.fname,Name) == 0) && (strcmp(x.lname,LName) ==0))
{
Isthere=true;

}
else
f1.read((char*)&x,sizeof(x));
}

f1.close();

if ((Isthere == true) && (strcmp(x.password,"") !=0))
{

// f1.clear();
f1.open(FileName.c_str(),ios::in); //opens file for reading
f1.read((char*)&x,sizeof(x)); //reads file

cout <<"\n" "\n" "\n" <<"Enter your password : ";
cin >> password;

if ((strcmp(x.password,password) ==0))
{
clear_screen();
cout <<"x.password is : " <<x.password <<endl;
cout <<"password is : " << password << endl;
cout <<"x.fname is : " << x.fname << endl;
cout <<"Name is : " << Name << endl;
cout <<"x.lname is : " << x.lname << endl;
cout <<"LName is : " << LName << endl;
_getch();
}

else
{

if (Isthere==false)
{
cout << "\n" <<"You must enter the correct password ";
cout << "\n" <<"You have 3 attempts";
cin >> password;

counter = counter+1;
if (counter==3)
{
exit(1);
}
}
}
}
else
{
cout <<"x.password is : "<< x.password;
cout <<"\n" "\n" "\n" "You must enter a password now : ";
cin >> x.password;
// f1.clear();
f1.open(FileName.c_str(),ios:

ut | ios::app);
CheckNameOnFile();
cout <<"x.password is : " << x.password;
}

}

if (RunOnce == true)
{
enter_password();
f1.write((char*)&x,sizeof(x));

cout << x.fname;
}

Isthere=false;

f1.open(FileName.c_str(),ios::in); //opens file for reading
f1.read((char*)&x,sizeof(x)); //reads file

clear_screen();

do {

//ERROR NEED WHILE LOOP TO FIND END OF FILE

while (!f1.eof() && !Isthere==true)
{
cout <<x.fname;
if ((strcmp(x.fname,Name) == 0) && (strcmp(x.lname,LName) ==0))
{
Isthere=true;
// exit(1);
}
else
f1.read((char*)&x,sizeof(x));
}

f1.close();

cout <<"******************************";
cout <<"\n" <<"This session is for";
cout <<"\n" <<x.fname <<" " << x.lname;
cout <<"\n" "\n";

cout <<" \n "<< "1 : Enter Pay";
cout << "\n "<< "2 : Display your details";
cout << "\n " << "3 : Change the path to install information";
cout <<" \n " << "9 : Quits the program";
cout <<"\n" "\n" "\n";

cin >> choice;

if (choice == 1)
{

f1.open(FileName.c_str(),ios:

ut | ios::app);

cout <<"\n" << "Enter pay : " ;
cin >> x.pay;

CheckNameOnFile();
exit(1);//exit program - another fix would be to set choice to 9
}

else if (choice == 2)
{
Isthere = false;
clear_screen();

if ((strcmp(x.fname,Name)==0) && (strcmp(x.lname,LName)==0))
{
Isthere=true;
payment=x.pay;
strcpy(Name,x.fname);
strcpy(LName,x.lname);
fflush(stdin);
cout <<"\n" <<"The following information is from disk";
cout <<"\n" <<"**************************************************";
cout <<"\n \n" <<"Your name : " << Name<< " " <<LName;
cout <<"\n";
cout <<"Your payment is : ";
cout <<payment;
cout <<"\n""\n""\n""\n";
while (choice !=1)
{
cout<<"Enter 1 to return to the menu : ";
cin >> choice;
if (choice == 1)
{
clear_screen();
}
}

}

}

else if (choice ==3)
{
cout <<"The installation path at the moment is : ";
cout <<FileName;
cout <<"Enter new installation path please :";
cin >> FileName;
cout <<"\n" "\n" "\n";
cout <<"The path has been changed to : ";
cout << FileName;
}

}
while (choice !=9);

return;
}

void enter_password()
{
clear_screen();

cout << "Enter a password - max 10 characters";

c=getch();

while (c!='\r' && c!='\n' && counter!=10)
{

cout <<"*";
c=getch();
pass[counter] = c;
counter++;
}
strcpy(x.password,pass);

}

void CheckNameOnFile()
{
f1.open(FileName.c_str(),ios::in);
f1.read((char*)&x,sizeof(x));
Isthere=false;

while(!f1.eof() && !Isthere==true)
{
if ((strcmp(x.fname,Name) == 0) && (strcmp(x.lname,LName) ==0))
{
Isthere=true;
ios:

os_type mark = f1.tellg();
f1.open(FileName.c_str(),ios:

ut|ios::app);
f1.write((char*)&x,sizeof(x));
f1.clear();
f1.seekg(mark);
f1.close();

}
f1.read((char*)&x,sizeof(x));
}

}

void clear_screen()
{
system("CLS");

return;
}

**sbrothy** · May 19th, 2003, 12:39 PM

Hi there! Just my two cents:

I think you could benefit from structuring your program better instead of just writing it as one big function. "Divide and conquer" as they say" :-). In other words: Break your program up in manageable parts and verify each part before you move on. As a side-benefit you'll remove redundancy along the way. I can imgainge than one of the first things you'd like to be able to do is to print, save and load your structure. Why don't you write small functions like:

[pseudocode]

Code:

void printPayroll()
{
    cout << "fname: [" << x.fname << "]\n";
    cout << "lname: [" << x.lname << "]\n";	
    cout << "pay: [" << x.pay << "]\n";	
    cout << "password: [" << x.password << "]\n";		
}


void savePayroll()
{
    ofstream ofs(FileName.c_str());
    if(!ofs)
    {
        cerr << "Error saving payroll.\n";		
    }
    ofs.write((char*)&x,sizeof(x));
}


void loadPayroll()
{
    ifstream ifs(FileName.c_str());
    if(!ifs)
    {
        cerr << "Error loading payroll.\n";
    }
    ifs.write((char*)&x,sizeof(x));
}

[/pseudocode]

and use those instead? I'm assuming that this is some sort of assignment, and I realize that you might want to write more than one structure to disk, but you probably get the idea :-)

In fact, the same goes for your menus:

[pseudocode]

Code:

int mainmenu()
{
    clear_screen();
    
    cout <<"******************************";
    cout <<"\n" <<"This session is for";
    cout <<"\n" <<x.fname <<" " << x.lname;
    cout <<"\n" "\n";

    cout <<" \n "<< "1 : Enter Pay";
    cout << "\n "<< "2 : Display your details";
    cout << "\n " << "3 : Change the path to install information";
    cout <<" \n " << "9 : Quits the program";
    cout <<"\n" "\n" "\n";

    int choice;
    cin >> choice;
    return choice;
}




void do_mainmenu()
{
    while(true)
    {
        switch(mainmenu())
        {
        case 1:
            do_paymenu();
            break;
        case 2:
            do_display_details();
            break;
        case 3:
            do_change_path();
            break;
        case 9:
            return; 
        default:
            break;
        }
    }
}

[/pseudocode]

Hope this helps.

Thread: Can someone please help - my program compiles but I get a assertion error

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Can someone please help - my program compiles but I get a assertion error

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